This documentation was generated automatically from the AVR Studio part description file ATmega161.pdf.

ANALOG COMPARATOR

ACSR - Analog Comparator Control And Status Register

sfrb ACSR = $08;

ACIS0 - Analog Comparator Interrupt Mode Select bit 0

#define ACIS0_BIT 0

#define ACIS0_MASK 1

These bits determine which comparator events that trigger the Analog Comparator interrupt.

ACIS1 - Analog Comparator Interrupt Mode Select bit 1

#define ACIS1_BIT 1

#define ACIS1_MASK 2

These bits determine which comparator events that trigger the Analog Comparator interrupt.

ACIC - Analog Comparator Input Capture Enable

#define ACIC_BIT 2

#define ACIC_MASK 4

When written logic one, this bit enables the Input Capture function in Timer/Counter1 to be triggered by the analog comparator. The comparator output is in this case directly connected to the Input Capture front-end logic, making the comparator utilize the noise canceler and edge select features of the Timer/Counter1 Input Capture interrupt. When written logic zero, no connection between the analog comparator and the Input Capture function exists. To make the comparator trigger the Timer/Counter1 Input Capture interrupt, the TICIE1 bit in the Timer Interrupt Mask Register (TIMSK) must be set

ACIE - Analog Comparator Interrupt Enable

#define ACIE_BIT 3

#define ACIE_MASK 8

When the ACIE bit is written logic one and the I-bit in the Status Register is set, the analog comparator interrupt is acti-vated. When written logic zero, the interrupt is disabled.

ACI - Analog Comparator Interrupt Flag

#define ACI_BIT 4

#define ACI_MASK 16

This bit is set by hardware when a comparator output event triggers the interrupt mode defined by ACIS1 and ACIS0. The Analog Comparator Interrupt routine is executed if the ACIE bit is set and the I-bit in SREG is set. ACI is cleared by hard-ware when executing the corresponding interrupt handling vector. Alternatively, ACI is cleared by writing a logic one to the flag.

ACO - Analog Compare Output

#define ACO_BIT 5

#define ACO_MASK 32

The output of the analog comparator is synchronized and then directly connected to ACO. The synchronization introduces a delay of 1-2 clock cycles.

AINBG - Analog Comparator Bandgap Select

#define AINBG_BIT 6

#define AINBG_MASK 64

When this bit is set, a fixed bandgap reference voltage replaces the positive input to the Analog Comparator. When this bit is cleared, AIN0 is applied to the positive input of the Analog Comparator. See ?Internal Voltage Reference? on page 42.

ACD - Analog Comparator Disable

#define ACD_BIT 7

#define ACD_MASK 128

When this bit is written logic one, the power to the analog comparator is switched off. This bit can be set at any time to turn off the analog comparator. This will reduce power consumption in active and idle mode. When changing the ACD bit, the Analog Comparator Interrupt must be disabled by clearing the ACIE bit in ACSR. Otherwise an interrupt can occur when the bit is changed.

SPI

The Serial Peripheral Interface (SPI) allows high-speed synchronous data transfer between the device and peripheral devices or between several AVR devices. The SPI includes the following features: ? Full-duplex, 3-wire Synchronous Data Transfer ? Master or Slave Operation ? LSB First or MSB First Data Transfer ? Seven Programmable Bit Rates ? End of Transmission Interrupt Flag ? Write Collision Flag Protection ? Wake-up from Idle Mode ? Double Speed (CK/2) Master SPI Mode

SPDR - SPI Data Register

sfrb SPDR = $0F;

SPDR0 - SPI Data Register bit 0

#define SPDR0_BIT 0

#define SPDR0_MASK 1

SPDR1 - SPI Data Register bit 1

#define SPDR1_BIT 1

#define SPDR1_MASK 2

SPDR2 - SPI Data Register bit 2

#define SPDR2_BIT 2

#define SPDR2_MASK 4

SPDR3 - SPI Data Register bit 3

#define SPDR3_BIT 3

#define SPDR3_MASK 8

SPDR4 - SPI Data Register bit 4

#define SPDR4_BIT 4

#define SPDR4_MASK 16

SPDR5 - SPI Data Register bit 5

#define SPDR5_BIT 5

#define SPDR5_MASK 32

SPDR6 - SPI Data Register bit 6

#define SPDR6_BIT 6

#define SPDR6_MASK 64

SPDR7 - SPI Data Register bit 7

#define SPDR7_BIT 7

#define SPDR7_MASK 128

SPSR - SPI Status Register

sfrb SPSR = $0E;

SPI2X - Double SPI Speed Bit

#define SPI2X_BIT 0

#define SPI2X_MASK 1

When this bit is written logic one the SPI speed (SCK Frequency) will be doubled when the SPI is in master mode (see Table 71). This means that the minimum SCK period will be 2 CPU clock periods. When the SPI is configured as Slave, the SPI is only guaranteed to work at f ck / 4 or lower. The SPI interface on the ATmega104 is also used for program memory and EEPROM downloading or uploading. See page 253 for serial programming and verification.

WCOL - Write Collision Flag

#define WCOL_BIT 6

#define WCOL_MASK 64

The WCOL bit is set if the SPI data register (SPDR) is written during a data transfer. The WCOL bit (and the SPIF bit) are cleared (zero) by first reading the SPI Status Register when WCOL is set (one), and then accessing the SPI Data Register.

SPIF - SPI Interrupt Flag

#define SPIF_BIT 7

#define SPIF_MASK 128

When a serial transfer is complete, the SPIF bit is set (one) and an interrupt is generated if SPIE in SPCR is set (one) and global interrupts are enabled. If SS is an input and is driven low when the SPI is in master mode, this will also set the SPIF flag. SPIF is cleared by hardware when executing the corresponding interrupt handling vector. Alternatively, the SPIF bit is cleared by first reading the SPI status register when SPIF is set (one), then accessing the SPI Data Register (SPDR).

SPCR - SPI Control Register

sfrb SPCR = $0D;

SPR0 - SPI Clock Rate Select 0

#define SPR0_BIT 0

#define SPR0_MASK 1

SPR1 - SPI Clock Rate Select 1

#define SPR1_BIT 1

#define SPR1_MASK 2

CPHA - Clock Phase

#define CPHA_BIT 2

#define CPHA_MASK 4

Refer to Figure 36 or Figure 37 for the functionality of this bit.

CPOL - Clock polarity

#define CPOL_BIT 3

#define CPOL_MASK 8

When this bit is set (one), SCK is high when idle. When CPOL is cleared (zero), SCK is low when idle. Refer to Figure 36 and Figure 37 for additional information.

MSTR - Master/Slave Select

#define MSTR_BIT 4

#define MSTR_MASK 16

This bit selects Master SPI mode when set (one), and Slave SPI mode when cleared (zero). If SS is configured as an input and is driven low while MSTR is set, MSTR will be cleared, and SPIF in SPSR will become set. The user will then have to set MSTR to re-enable SPI master mode.

DORD - Data Order

#define DORD_BIT 5

#define DORD_MASK 32

When the DORD bit is set (one), the LSB of the data word is transmitted first. When the DORD bit is cleared (zero), the MSB of the data word is transmitted first.

SPE - SPI Enable

#define SPE_BIT 6

#define SPE_MASK 64

When the SPE bit is set (one), the SPI is enabled. This bit must be set to enable any SPI operations.

SPIE - SPI Interrupt Enable

#define SPIE_BIT 7

#define SPIE_MASK 128

This bit causes the SPI interrupt to be executed if SPIF bit in the SPSR register is set and the global interrupts are enabled.

USART0

The Universal Synchronous and Asynchronous serial Receiver and Transmitter (USART) is a highly flexible serial communication device. The main features are: ? Full Duplex Operation (Independent Serial Receive and Transmit Registers) ? Asynchronous or Synchronous Operation ? Master or Slave Clocked Synchronous Operation ? High Resolution Baud Rate Generator ? Supports Serial Frames with 5, 6, 7, 8 or 9 Data Bits and 1 or 2 Stop Bits ? Odd or Even Parity Generation and Parity Check Supported by Hardware ? Data OverRun Detection ? Framing Error Detection ? Noise Filtering Includes False Start Bit Detection and Digital Low Pass Filter ? Three Separate Interrupts on TX Complete, TX Data Register Empty and RX Complete ? Multi-processor Communication Mode ? Double Speed Asynchronous Com

UDR0 - USART I/O Data Register

sfrb UDR0 = $0C;

UDR00 - USART I/O Data Register bit 0

#define UDR00_BIT 0

#define UDR00_MASK 1

UDR01 - USART I/O Data Register bit 1

#define UDR01_BIT 1

#define UDR01_MASK 2

UDR02 - USART I/O Data Register bit 2

#define UDR02_BIT 2

#define UDR02_MASK 4

UDR03 - USART I/O Data Register bit 3

#define UDR03_BIT 3

#define UDR03_MASK 8

UDR04 - USART I/O Data Register bit 4

#define UDR04_BIT 4

#define UDR04_MASK 16

UDR05 - USART I/O Data Register bit 5

#define UDR05_BIT 5

#define UDR05_MASK 32

UDR06 - USART I/O Data Register bit 6

#define UDR06_BIT 6

#define UDR06_MASK 64

UDR07 - USART I/O Data Register bit 7

#define UDR07_BIT 7

#define UDR07_MASK 128

UCSR0A - USART Control and Status Register A

sfrb UCSR0A = $0B;

MPCM0 - Multi-processor Communication Mode

#define MPCM0_BIT 0

#define MPCM0_MASK 1

This bit enables the Multi-processor Communication Mode. When the MPCM bit is written to one, all the incoming frames received by the USART receiver that do not contain address information will be ignored. The transmitter is unaffected by the MPCM setting. For more detailed information see ?Multi-processor Communication Mode? on page 152.

U2X0 - Double the USART transmission speed

#define U2X0_BIT 1

#define U2X0_MASK 2

This bit only has effect for the asynchronous operation. Write this bit to zero when using synchronous operation. Writing this bit to one will reduce the divisor of the baud rate divider from 16 to 8 effectively doubling the transfer rate for asynchronous communication.

OR0 - Data overRun

#define OR0_BIT 3

#define OR0_MASK 8

This bit is set if an Overrun condition is detected, i.e. when a character already present in the UDR0 register is not read before the next character has been shifted into the Receiver Shift register. The OR bit is buffered, which means that it will be set once the valid data still in UDR0E is read. The OR bit is cleared (zero) when data is received and transferred to UDR0.

FE0 - Framing Error

#define FE0_BIT 4

#define FE0_MASK 16

This bit is set if a Framing Error condition is detected, i.e. when the stop bit of an incoming character is zero. The FE bit is cleared when the stop bit of received data is one.

UDRE0 - USART Data Register Empty

#define UDRE0_BIT 5

#define UDRE0_MASK 32

This bit is set (one) when a character written to UDR0 is transferred to the Transmit shift register. Setting of this bit indicates that the transmitter is ready to receive a new character for transmission. When the UDR0IE bit in UCR is set, the USART Transmit Complete interrupt to be executed as long as UDR0E is set. UDR0E is cleared by writing UDR0. When interrupt-driven data transmittal is used, the USART Data Register Empty Interrupt routine must write UDR0 in order to clear UDR0E, otherwise a new interrupt will occur once the interrupt routine terminates. UDR0E is set (one) during reset to indicate that the transmitter is r

TXC0 - USART Transmitt Complete

#define TXC0_BIT 6

#define TXC0_MASK 64

This bit is set (one) when the entire character (including the stop bit) in the Transmit Shift register has been shifted out and no new data has been written to UDR0. This flag is especially useful in half-duplex communications interfaces, where a transmitting application must enter receive mode and free the communications bus immediately after completing the transmission. When the TXCIE bit in UCR is set, setting of TXC causes the USART Transmit Complete interrupt to be executed. TXC is cleared by hardware when executing the corresponding interrupt handling vector. Alternatively, the TXC bit is cleared (zero) by writing a logical one to t

RXC0 - USART Receive Complete

#define RXC0_BIT 7

#define RXC0_MASK 128

This bit is set (one) when a received character is transferred from the Receiver Shift register to UDR0. The bit is set regardless of any detected framing errors. When the RXCIE bit in UCR is set, the USART Receive Complete interrupt will be executed when RXC is set(one). RXC is cleared by reading UDR0. When interrupt-driven data reception is used, the USART Receive Complete Interrupt routine must read UDR0 in order to clear RXC, otherwise a new interrupt will occur once the interrupt routine terminates.

UCSR0B - USART Control and Status Register B

sfrb UCSR0B = $0A;

TXB80 - Transmit Data Bit 8

#define TXB80_BIT 0

#define TXB80_MASK 1

TXB8 is the 9th data bit in the character to be transmitted when operating with serial frames with 9 data bits. Must be writ-ten before writing the low bits to UDR0.

RXB80 - Receive Data Bit 8

#define RXB80_BIT 1

#define RXB80_MASK 2

RXB8 is the 9th data bit of the received character when operating with serial frames with 9 data bits. Must be read before reading the low bits from UDR0.

CHR90 - 9-Bit Character

#define CHR90_BIT 2

#define CHR90_MASK 4

TXEN0 - Transmitter Enable

#define TXEN0_BIT 3

#define TXEN0_MASK 8

Writing this bit to one enables the USART transmitter. The transmitter will override normal port operation for the TxD pin when enabled. The disabling of the transmitter (writing TXEN to zero) will not become effective until ongoing and pending transmissions are completed, i.e. when the transmit shift register and transmit buffer register does not contain data to be transmitted. When disabled, the transmitter will no longer override the TxD port.

RXEN0 - Receiver Enable

#define RXEN0_BIT 4

#define RXEN0_MASK 16

Writing this bit to one enables the USART receiver. The receiver will override normal port operation for the RxD pin when enabled. Disabling the receiver will flush the receive buffer invalidating the FE, DOR and PE flags.

UDR0IE0 - USART Data register Empty Interrupt Enable

#define UDR0IE0_BIT 5

#define UDR0IE0_MASK 32

Writing this bit to one enables interrupt on the UDR0E flag. A Data Register Empty interrupt will be generated only if the UDR0IE bit is written to one, the global interrupt flag in SREG is written to one and the UDR0E bit in UCSR0A is set.

TXCIE0 - TX Complete Interrupt Enable

#define TXCIE0_BIT 6

#define TXCIE0_MASK 64

Writing this bit to one enables interrupt on the TXC flag. A USART Transmit Complete interrupt will be generated only if the TXCIE bit is written to one, the global interrupt flag in SREG is written to one and the TXC bit in UCSR0A is set.

RXCIE0 - RX Complete Interrupt Enable

#define RXCIE0_BIT 7

#define RXCIE0_MASK 128

Writing this bit to one enables interrupt on the RXC flag. A USART Receive Complete interrupt will be generated only if the RXCIE bit is written to one, the global interrupt flag in SREG is written to one and the RXC bit in UCSR0A is set.

UBRR0 - USART Baud Rate Register Byte

sfrb UBRR0 = $09;

UBRR00 - USART Baud Rate Register bit 0

#define UBRR00_BIT 0

#define UBRR00_MASK 1

UBRR01 - USART Baud Rate Register bit 1

#define UBRR01_BIT 1

#define UBRR01_MASK 2

UBRR02 - USART Baud Rate Register bit 2

#define UBRR02_BIT 2

#define UBRR02_MASK 4

UBRR03 - USART Baud Rate Register bit 3

#define UBRR03_BIT 3

#define UBRR03_MASK 8

UBRR04 - USART Baud Rate Register bit 4

#define UBRR04_BIT 4

#define UBRR04_MASK 16

UBRR05 - USART Baud Rate Register bit 5

#define UBRR05_BIT 5

#define UBRR05_MASK 32

UBRR06 - USART Baud Rate Register bit 6

#define UBRR06_BIT 6

#define UBRR06_MASK 64

UBRR07 - USART Baud Rate Register bit 7

#define UBRR07_BIT 7

#define UBRR07_MASK 128

UBRRHI - High Byte Baud Rate Register

sfrb UBRRHI = $20;

UBRRHI00 - High Byte Baud Rate Register Port 0 Bit 0

#define UBRRHI00_BIT 0

#define UBRRHI00_MASK 1

UBRRHI01 - High Byte Baud Rate Register Port 0 Bit 1

#define UBRRHI01_BIT 1

#define UBRRHI01_MASK 2

UBRRHI02 - High Byte Baud Rate Register Port 0 Bit 2

#define UBRRHI02_BIT 2

#define UBRRHI02_MASK 4

UBRRHI03 - High Byte Baud Rate Register Port 0 Bit 3

#define UBRRHI03_BIT 3

#define UBRRHI03_MASK 8

USART1

The Universal Synchronous and Asynchronous serial Receiver and Transmitter (USART) is a highly flexible serial communication device. The main features are: ? Full Duplex Operation (Independent Serial Receive and Transmit Registers) ? Asynchronous or Synchronous Operation ? Master or Slave Clocked Synchronous Operation ? High Resolution Baud Rate Generator ? Supports Serial Frames with 5, 6, 7, 8 or 9 Data Bits and 1 or 2 Stop Bits ? Odd or Even Parity Generation and Parity Check Supported by Hardware ? Data OverRun Detection ? Framing Error Detection ? Noise Filtering Includes False Start Bit Detection and Digital Low Pass Filter ? Three Separate Interrupts on TX Complete, TX Data Register Empty and RX Complete ? Multi-processor Communication Mode ? Double Speed Asynchronous Com

UDR1 - USART I/O Data Register

sfrb UDR1 = $03;

UDR10 - USART I/O Data Register bit 0

#define UDR10_BIT 0

#define UDR10_MASK 1

UDR11 - USART I/O Data Register bit 1

#define UDR11_BIT 1

#define UDR11_MASK 2

UDR12 - USART I/O Data Register bit 2

#define UDR12_BIT 2

#define UDR12_MASK 4

UDR13 - USART I/O Data Register bit 3

#define UDR13_BIT 3

#define UDR13_MASK 8

UDR14 - USART I/O Data Register bit 4

#define UDR14_BIT 4

#define UDR14_MASK 16

UDR15 - USART I/O Data Register bit 5

#define UDR15_BIT 5

#define UDR15_MASK 32

UDR16 - USART I/O Data Register bit 6

#define UDR16_BIT 6

#define UDR16_MASK 64

UDR17 - USART I/O Data Register bit 7

#define UDR17_BIT 7

#define UDR17_MASK 128

UCSR1A - USART Control and Status Register A

sfrb UCSR1A = $02;

MPCM1 - Multi-processor Communication Mode

#define MPCM1_BIT 0

#define MPCM1_MASK 1

This bit enables the Multi-processor Communication Mode. When the MPCM bit is written to one, all the incoming frames received by the USART receiver that do not contain address information will be ignored. The transmitter is unaffected by the MPCM setting. For more detailed information see ?Multi-processor Communication Mode? on page 152.

U2X1 - Double the USART transmission speed

#define U2X1_BIT 1

#define U2X1_MASK 2

This bit only has effect for the asynchronous operation. Write this bit to zero when using synchronous operation. Writing this bit to one will reduce the divisor of the baud rate divider from 16 to 8 effectively doubling the transfer rate for asynchronous communication.

OR1 - Data overRun

#define OR1_BIT 3

#define OR1_MASK 8

This bit is set if an Overrun condition is detected, i.e. when a character already present in the UDR1 register is not read before the next character has been shifted into the Receiver Shift register. The OR bit is buffered, which means that it will be set once the valid data still in UDR1E is read. The OR bit is cleared (zero) when data is received and transferred to UDR1.

FE1 - Framing Error

#define FE1_BIT 4

#define FE1_MASK 16

This bit is set if a Framing Error condition is detected, i.e. when the stop bit of an incoming character is zero. The FE bit is cleared when the stop bit of received data is one.

UDRE1 - USART Data Register Empty

#define UDRE1_BIT 5

#define UDRE1_MASK 32

This bit is set (one) when a character written to UDR1 is transferred to the Transmit shift register. Setting of this bit indicates that the transmitter is ready to receive a new character for transmission. When the UDR1IE bit in UCR is set, the USART Transmit Complete interrupt to be executed as long as UDR1E is set. UDR1E is cleared by writing UDR1. When interrupt-driven data transmittal is used, the USART Data Register Empty Interrupt routine must write UDR1 in order to clear UDR1E, otherwise a new interrupt will occur once the interrupt routine terminates. UDR1E is set (one) during reset to indicate that the transmitter is

TXC1 - USART Transmitt Complete

#define TXC1_BIT 6

#define TXC1_MASK 64

This bit is set (one) when the entire character (including the stop bit) in the Transmit Shift register has been shifted out and no new data has been written to UDR1. This flag is especially useful in half-duplex communications interfaces, where a transmitting application must enter receive mode and free the communications bus immediately after completing the transmission. When the TXCIE bit in UCR is set, setting of TXC causes the USART Transmit Complete interrupt to be executed. TXC is cleared by hardware when executing the corresponding interrupt handling vector. Alternatively, the TXC bit is cleared (zero) by writing a logical one to

RXC1 - USART Receive Complete

#define RXC1_BIT 7

#define RXC1_MASK 128

This bit is set (one) when a received character is transferred from the Receiver Shift register to UDR1. The bit is set regardless of any detected framing errors. When the RXCIE bit in UCR is set, the USART Receive Complete interrupt will be executed when RXC is set(one). RXC is cleared by reading UDR1. When interrupt-driven data reception is used, the USART Receive Complete Interrupt routine must read UDR1 in order to clear RXC, otherwise a new interrupt will occur once the interrupt routine terminates.

UCSR1B - USART Control and Status Register B

sfrb UCSR1B = $01;

TXB81 - Transmit Data Bit 8

#define TXB81_BIT 0

#define TXB81_MASK 1

TXB8 is the 9th data bit in the character to be transmitted when operating with serial frames with 9 data bits. Must be writ-ten before writing the low bits to UDR1.

RXB81 - Receive Data Bit 8

#define RXB81_BIT 1

#define RXB81_MASK 2

RXB8 is the 9th data bit of the received character when operating with serial frames with 9 data bits. Must be read before reading the low bits from UDR1.

CHR91 - 9-Bit Character

#define CHR91_BIT 2

#define CHR91_MASK 4

TXEN1 - Transmitter Enable

#define TXEN1_BIT 3

#define TXEN1_MASK 8

Writing this bit to one enables the USART transmitter. The transmitter will override normal port operation for the TxD pin when enabled. The disabling of the transmitter (writing TXEN to zero) will not become effective until ongoing and pending transmissions are completed, i.e. when the transmit shift register and transmit buffer register does not contain data to be transmitted. When disabled, the transmitter will no longer override the TxD port.

RXEN1 - Receiver Enable

#define RXEN1_BIT 4

#define RXEN1_MASK 16

Writing this bit to one enables the USART receiver. The receiver will override normal port operation for the RxD pin when enabled. Disabling the receiver will flush the receive buffer invalidating the FE, DOR and PE flags.

UDR1IE1 - USART Data register Empty Interrupt Enable

#define UDR1IE1_BIT 5

#define UDR1IE1_MASK 32

Writing this bit to one enables interrupt on the UDR1E flag. A Data Register Empty interrupt will be generated only if the UDR1IE bit is written to one, the global interrupt flag in SREG is written to one and the UDR1E bit in UCSR1A is set.

TXCIE1 - TX Complete Interrupt Enable

#define TXCIE1_BIT 6

#define TXCIE1_MASK 64

Writing this bit to one enables interrupt on the TXC flag. A USART Transmit Complete interrupt will be generated only if the TXCIE bit is written to one, the global interrupt flag in SREG is written to one and the TXC bit in UCSR1A is set.

RXCIE1 - RX Complete Interrupt Enable

#define RXCIE1_BIT 7

#define RXCIE1_MASK 128

Writing this bit to one enables interrupt on the RXC flag. A USART Receive Complete interrupt will be generated only if the RXCIE bit is written to one, the global interrupt flag in SREG is written to one and the RXC bit in UCSR1A is set.

UBRR1 - USART Baud Rate Register Byte

sfrb UBRR1 = $00;

UBRR10 - USART Baud Rate Register bit 0

#define UBRR10_BIT 0

#define UBRR10_MASK 1

UBRR11 - USART Baud Rate Register bit 1

#define UBRR11_BIT 1

#define UBRR11_MASK 2

UBRR12 - USART Baud Rate Register bit 2

#define UBRR12_BIT 2

#define UBRR12_MASK 4

UBRR13 - USART Baud Rate Register bit 3

#define UBRR13_BIT 3

#define UBRR13_MASK 8

UBRR14 - USART Baud Rate Register bit 4

#define UBRR14_BIT 4

#define UBRR14_MASK 16

UBRR15 - USART Baud Rate Register bit 5

#define UBRR15_BIT 5

#define UBRR15_MASK 32

UBRR16 - USART Baud Rate Register bit 6

#define UBRR16_BIT 6

#define UBRR16_MASK 64

UBRR17 - USART Baud Rate Register bit 7

#define UBRR17_BIT 7

#define UBRR17_MASK 128

UBRRHI - high Byte Baud Rate Register

sfrb UBRRHI = $20;

UBRRHI10 - High Byte Baud Rate Register Port 0 Bit 0

#define UBRRHI10_BIT 4

#define UBRRHI10_MASK 16

UBRRHI11 - High Byte Baud Rate Register Port 0 Bit 1

#define UBRRHI11_BIT 5

#define UBRRHI11_MASK 32

UBRRHI12 - High Byte Baud Rate Register Port 0 Bit 2

#define UBRRHI12_BIT 6

#define UBRRHI12_MASK 64

UBRRHI13 - High Byte Baud Rate Register Port 0 Bit 3

#define UBRRHI13_BIT 7

#define UBRRHI13_MASK 128

PORTA

PORTA - Port A Data Register

sfrb PORTA = $1B;

PORTA0 - Port A Data Register bit 0

#define PORTA0_BIT 0

#define PORTA0_MASK 1

PORTA1 - Port A Data Register bit 1

#define PORTA1_BIT 1

#define PORTA1_MASK 2

PORTA2 - Port A Data Register bit 2

#define PORTA2_BIT 2

#define PORTA2_MASK 4

PORTA3 - Port A Data Register bit 3

#define PORTA3_BIT 3

#define PORTA3_MASK 8

PORTA4 - Port A Data Register bit 4

#define PORTA4_BIT 4

#define PORTA4_MASK 16

PORTA5 - Port A Data Register bit 5

#define PORTA5_BIT 5

#define PORTA5_MASK 32

PORTA6 - Port A Data Register bit 6

#define PORTA6_BIT 6

#define PORTA6_MASK 64

PORTA7 - Port A Data Register bit 7

#define PORTA7_BIT 7

#define PORTA7_MASK 128

DDRA - Port A Data Direction Register

sfrb DDRA = $1A;

DDA0 - Data Direction Register, Port A, bit 0

#define DDA0_BIT 0

#define DDA0_MASK 1

DDA1 - Data Direction Register, Port A, bit 1

#define DDA1_BIT 1

#define DDA1_MASK 2

DDA2 - Data Direction Register, Port A, bit 2

#define DDA2_BIT 2

#define DDA2_MASK 4

DDA3 - Data Direction Register, Port A, bit 3

#define DDA3_BIT 3

#define DDA3_MASK 8

DDA4 - Data Direction Register, Port A, bit 4

#define DDA4_BIT 4

#define DDA4_MASK 16

DDA5 - Data Direction Register, Port A, bit 5

#define DDA5_BIT 5

#define DDA5_MASK 32

DDA6 - Data Direction Register, Port A, bit 6

#define DDA6_BIT 6

#define DDA6_MASK 64

DDA7 - Data Direction Register, Port A, bit 7

#define DDA7_BIT 7

#define DDA7_MASK 128

PINA - Port A Input Pins

sfrb PINA = $19;

PINA0 - Input Pins, Port A bit 0

#define PINA0_BIT 0

#define PINA0_MASK 1

PINA1 - Input Pins, Port A bit 1

#define PINA1_BIT 1

#define PINA1_MASK 2

PINA2 - Input Pins, Port A bit 2

#define PINA2_BIT 2

#define PINA2_MASK 4

PINA3 - Input Pins, Port A bit 3

#define PINA3_BIT 3

#define PINA3_MASK 8

PINA4 - Input Pins, Port A bit 4

#define PINA4_BIT 4

#define PINA4_MASK 16

PINA5 - Input Pins, Port A bit 5

#define PINA5_BIT 5

#define PINA5_MASK 32

PINA6 - Input Pins, Port A bit 6

#define PINA6_BIT 6

#define PINA6_MASK 64

PINA7 - Input Pins, Port A bit 7

#define PINA7_BIT 7

#define PINA7_MASK 128

PORTB

PORTB - Port B Data Register

sfrb PORTB = $18;

PORTB0 - Port B Data Register bit 0

#define PORTB0_BIT 0

#define PORTB0_MASK 1

PORTB1 - Port B Data Register bit 1

#define PORTB1_BIT 1

#define PORTB1_MASK 2

PORTB2 - Port B Data Register bit 2

#define PORTB2_BIT 2

#define PORTB2_MASK 4

PORTB3 - Port B Data Register bit 3

#define PORTB3_BIT 3

#define PORTB3_MASK 8

PORTB4 - Port B Data Register bit 4

#define PORTB4_BIT 4

#define PORTB4_MASK 16

PORTB5 - Port B Data Register bit 5

#define PORTB5_BIT 5

#define PORTB5_MASK 32

PORTB6 - Port B Data Register bit 6

#define PORTB6_BIT 6

#define PORTB6_MASK 64

PORTB7 - Port B Data Register bit 7

#define PORTB7_BIT 7

#define PORTB7_MASK 128

DDRB - Port B Data Direction Register

sfrb DDRB = $17;

DDB0 - Port B Data Direction Register bit 0

#define DDB0_BIT 0

#define DDB0_MASK 1

DDB1 - Port B Data Direction Register bit 1

#define DDB1_BIT 1

#define DDB1_MASK 2

DDB2 - Port B Data Direction Register bit 2

#define DDB2_BIT 2

#define DDB2_MASK 4

DDB3 - Port B Data Direction Register bit 3

#define DDB3_BIT 3

#define DDB3_MASK 8

DDB4 - Port B Data Direction Register bit 4

#define DDB4_BIT 4

#define DDB4_MASK 16

DDB5 - Port B Data Direction Register bit 5

#define DDB5_BIT 5

#define DDB5_MASK 32

DDB6 - Port B Data Direction Register bit 6

#define DDB6_BIT 6

#define DDB6_MASK 64

DDB7 - Port B Data Direction Register bit 7

#define DDB7_BIT 7

#define DDB7_MASK 128

PINB - Port B Input Pins

sfrb PINB = $16;

PINB0 - Port B Input Pins bit 0

#define PINB0_BIT 0

#define PINB0_MASK 1

PINB1 - Port B Input Pins bit 1

#define PINB1_BIT 1

#define PINB1_MASK 2

PINB2 - Port B Input Pins bit 2

#define PINB2_BIT 2

#define PINB2_MASK 4

PINB3 - Port B Input Pins bit 3

#define PINB3_BIT 3

#define PINB3_MASK 8

PINB4 - Port B Input Pins bit 4

#define PINB4_BIT 4

#define PINB4_MASK 16

PINB5 - Port B Input Pins bit 5

#define PINB5_BIT 5

#define PINB5_MASK 32

PINB6 - Port B Input Pins bit 6

#define PINB6_BIT 6

#define PINB6_MASK 64

PINB7 - Port B Input Pins bit 7

#define PINB7_BIT 7

#define PINB7_MASK 128

PORTC

PORTC - Port C Data Register

sfrb PORTC = $15;

PORTC0 - Port C Data Register bit 0

#define PORTC0_BIT 0

#define PORTC0_MASK 1

PORTC1 - Port C Data Register bit 1

#define PORTC1_BIT 1

#define PORTC1_MASK 2

PORTC2 - Port C Data Register bit 2

#define PORTC2_BIT 2

#define PORTC2_MASK 4

PORTC3 - Port C Data Register bit 3

#define PORTC3_BIT 3

#define PORTC3_MASK 8

PORTC4 - Port C Data Register bit 4

#define PORTC4_BIT 4

#define PORTC4_MASK 16

PORTC5 - Port C Data Register bit 5

#define PORTC5_BIT 5

#define PORTC5_MASK 32

PORTC6 - Port C Data Register bit 6

#define PORTC6_BIT 6

#define PORTC6_MASK 64

PORTC7 - Port C Data Register bit 7

#define PORTC7_BIT 7

#define PORTC7_MASK 128

DDRC - Port C Data Direction Register

sfrb DDRC = $14;

DDC0 - Port C Data Direction Register bit 0

#define DDC0_BIT 0

#define DDC0_MASK 1

DDC1 - Port C Data Direction Register bit 1

#define DDC1_BIT 1

#define DDC1_MASK 2

DDC2 - Port C Data Direction Register bit 2

#define DDC2_BIT 2

#define DDC2_MASK 4

DDC3 - Port C Data Direction Register bit 3

#define DDC3_BIT 3

#define DDC3_MASK 8

DDC4 - Port C Data Direction Register bit 4

#define DDC4_BIT 4

#define DDC4_MASK 16

DDC5 - Port C Data Direction Register bit 5

#define DDC5_BIT 5

#define DDC5_MASK 32

DDC6 - Port C Data Direction Register bit 6

#define DDC6_BIT 6

#define DDC6_MASK 64

DDC7 - Port C Data Direction Register bit 7

#define DDC7_BIT 7

#define DDC7_MASK 128

PINC - Port C Input Pins

sfrb PINC = $13;

PINC0 - Port C Input Pins bit 0

#define PINC0_BIT 0

#define PINC0_MASK 1

PINC1 - Port C Input Pins bit 1

#define PINC1_BIT 1

#define PINC1_MASK 2

PINC2 - Port C Input Pins bit 2

#define PINC2_BIT 2

#define PINC2_MASK 4

PINC3 - Port C Input Pins bit 3

#define PINC3_BIT 3

#define PINC3_MASK 8

PINC4 - Port C Input Pins bit 4

#define PINC4_BIT 4

#define PINC4_MASK 16

PINC5 - Port C Input Pins bit 5

#define PINC5_BIT 5

#define PINC5_MASK 32

PINC6 - Port C Input Pins bit 6

#define PINC6_BIT 6

#define PINC6_MASK 64

PINC7 - Port C Input Pins bit 7

#define PINC7_BIT 7

#define PINC7_MASK 128

PORTD

PORTD - Port D Data Register

sfrb PORTD = $12;

PORTD0 - Port D Data Register bit 0

#define PORTD0_BIT 0

#define PORTD0_MASK 1

PORTD1 - Port D Data Register bit 1

#define PORTD1_BIT 1

#define PORTD1_MASK 2

PORTD2 - Port D Data Register bit 2

#define PORTD2_BIT 2

#define PORTD2_MASK 4

PORTD3 - Port D Data Register bit 3

#define PORTD3_BIT 3

#define PORTD3_MASK 8

PORTD4 - Port D Data Register bit 4

#define PORTD4_BIT 4

#define PORTD4_MASK 16

PORTD5 - Port D Data Register bit 5

#define PORTD5_BIT 5

#define PORTD5_MASK 32

PORTD6 - Port D Data Register bit 6

#define PORTD6_BIT 6

#define PORTD6_MASK 64

PORTD7 - Port D Data Register bit 7

#define PORTD7_BIT 7

#define PORTD7_MASK 128

DDRD - Port D Data Direction Register

sfrb DDRD = $11;

DDD0 - Port D Data Direction Register bit 0

#define DDD0_BIT 0

#define DDD0_MASK 1

DDD1 - Port D Data Direction Register bit 1

#define DDD1_BIT 1

#define DDD1_MASK 2

DDD2 - Port D Data Direction Register bit 2

#define DDD2_BIT 2

#define DDD2_MASK 4

DDD3 - Port D Data Direction Register bit 3

#define DDD3_BIT 3

#define DDD3_MASK 8

DDD4 - Port D Data Direction Register bit 4

#define DDD4_BIT 4

#define DDD4_MASK 16

DDD5 - Port D Data Direction Register bit 5

#define DDD5_BIT 5

#define DDD5_MASK 32

DDD6 - Port D Data Direction Register bit 6

#define DDD6_BIT 6

#define DDD6_MASK 64

DDD7 - Port D Data Direction Register bit 7

#define DDD7_BIT 7

#define DDD7_MASK 128

PIND - Port D Input Pins

sfrb PIND = $10;

PIND0 - Port D Input Pins bit 0

#define PIND0_BIT 0

#define PIND0_MASK 1

PIND1 - Port D Input Pins bit 1

#define PIND1_BIT 1

#define PIND1_MASK 2

PIND2 - Port D Input Pins bit 2

#define PIND2_BIT 2

#define PIND2_MASK 4

PIND3 - Port D Input Pins bit 3

#define PIND3_BIT 3

#define PIND3_MASK 8

PIND4 - Port D Input Pins bit 4

#define PIND4_BIT 4

#define PIND4_MASK 16

PIND5 - Port D Input Pins bit 5

#define PIND5_BIT 5

#define PIND5_MASK 32

PIND6 - Port D Input Pins bit 6

#define PIND6_BIT 6

#define PIND6_MASK 64

PIND7 - Port D Input Pins bit 7

#define PIND7_BIT 7

#define PIND7_MASK 128

PORTE

PORTE - Port E Data Register

sfrb PORTE = $07;

PORTE0

#define PORTE0_BIT 0

#define PORTE0_MASK 1

PORTE1

#define PORTE1_BIT 1

#define PORTE1_MASK 2

PORTE2

#define PORTE2_BIT 2

#define PORTE2_MASK 4

DDRE - Port E Data Direction Register

sfrb DDRE = $06;

DDE0

#define DDE0_BIT 0

#define DDE0_MASK 1

DDE1

#define DDE1_BIT 1

#define DDE1_MASK 2

DDE2

#define DDE2_BIT 2

#define DDE2_MASK 4

PINE - Port E Input Pins

sfrb PINE = $05;

PINE0

#define PINE0_BIT 0

#define PINE0_MASK 1

PINE1

#define PINE1_BIT 1

#define PINE1_MASK 2

PINE2

#define PINE2_BIT 2

#define PINE2_MASK 4

EEPROM

EEPROM Read/Write Access. The EEPROM access registers are accessible in the I/O space. The write access time for the EEPROM is given in Table 1. A self-timing function, however, lets the user software detect when the next byte can be written. If the user code contains instructions that write the EEPROM, some precautions must be taken. In heavily filtered power supplies, V CC is likely to rise or fall slowly on power-up/down. This causes the device for some period of time to run at a voltage lower than specified as minimum for the clock frequency used. See ?Preventing EEPROM Corruption? on page 19. for details on how to avoid problems in these situations.In order to prevent unintentional EEPROM writes, a specific write procedure must be followed. Refer to the description of the EEPROM Control Register for details on this. When the EEPROM is read, the CPU is halted for four clock cycles before the next instruction is executed. When theEEPROM is written, the CPU is halted for two clock cycles before the next instruction is execute

EEARH - EEPROM Address Register High Byte

sfrb EEARH = $1F;

EEAR8 - EEPROM Read/Write Access Bit 8

#define EEAR8_BIT 0

#define EEAR8_MASK 1

EEARL - EEPROM Address Register Low Byte

sfrb EEARL = $1E;

EEAR0 - EEPROM Read/Write Access Bit 0

#define EEAR0_BIT 0

#define EEAR0_MASK 1

EEAR1 - EEPROM Read/Write Access Bit 1

#define EEAR1_BIT 1

#define EEAR1_MASK 2

EEAR2 - EEPROM Read/Write Access Bit 2

#define EEAR2_BIT 2

#define EEAR2_MASK 4

EEAR3 - EEPROM Read/Write Access Bit 3

#define EEAR3_BIT 3

#define EEAR3_MASK 8

EEAR4 - EEPROM Read/Write Access Bit 4

#define EEAR4_BIT 4

#define EEAR4_MASK 16

EEAR5 - EEPROM Read/Write Access Bit 5

#define EEAR5_BIT 5

#define EEAR5_MASK 32

EEAR6 - EEPROM Read/Write Access Bit 6

#define EEAR6_BIT 6

#define EEAR6_MASK 64

EEAR7 - EEPROM Read/Write Access Bit 7

#define EEAR7_BIT 7

#define EEAR7_MASK 128

EEDR - EEPROM Data Register

sfrb EEDR = $1D;

EEDR0 - EEPROM Data Register bit 0

#define EEDR0_BIT 0

#define EEDR0_MASK 1

EEDR1 - EEPROM Data Register bit 1

#define EEDR1_BIT 1

#define EEDR1_MASK 2

EEDR2 - EEPROM Data Register bit 2

#define EEDR2_BIT 2

#define EEDR2_MASK 4

EEDR3 - EEPROM Data Register bit 3

#define EEDR3_BIT 3

#define EEDR3_MASK 8

EEDR4 - EEPROM Data Register bit 4

#define EEDR4_BIT 4

#define EEDR4_MASK 16

EEDR5 - EEPROM Data Register bit 5

#define EEDR5_BIT 5

#define EEDR5_MASK 32

EEDR6 - EEPROM Data Register bit 6

#define EEDR6_BIT 6

#define EEDR6_MASK 64

EEDR7 - EEPROM Data Register bit 7

#define EEDR7_BIT 7

#define EEDR7_MASK 128

EECR - EEPROM Control Register

sfrb EECR = $1C;

EERE - EEPROM Read Enable

#define EERE_BIT 0

#define EERE_MASK 1

The EEPROM Read Enable Signal EERE is the read strobe to the EEPROM. When the correct address is set up in the EEAR register, the EERE bit must be written to a logic one to trigger the EEPROM read. The EEPROM read access takes one instruction, and the requested data is available immediately. When the EEPROM is read, the CPU is halted for four cycles before the next instruction is executed. The user should poll the EEWE bit before starting the read operation. If a write operation is in progress, it is neither possible to read the EEPROM, nor to change the EEAR register. The calibrated oscillator is used to time the EEPROM accesses. Table 1 lists the typical programming time for EEPROM access from the CPU

EEWE - EEPROM Write Enable

#define EEWE_BIT 1

#define EEWE_MASK 2

The EEPROM Write Enable Signal EEWE is the write strobe to the EEPROM. When address and data are correctly set up, the EEWE bit must be set to write the value into the EEPROM. The EEMWE bit must be set when the logical one is written to EEWE, otherwise no EEPROM write takes place. The following procedure should be followed when writing the EEPROM (the order of steps 3 and 4 is not essential): 1. Wait until EEWE becomes zero. 2. Wait until SPMEN in SPMCR becomes zero. 3. Write new EEPROM address to EEAR (optional). 4. Write new EEPROM data to EEDR (optional). 5. Write a logical one to the EEMWE bit while writing a zero to EEWE in EECR. 6. Within four clock cycles after setting EEMWE, write a logical one to EEWE. The EEPROM can not be programmed during a CPU write to the Flash memory. The software must check that the Flash programming is completed before initiating a new EEPROM write. Step 2 is only relevant if the software contains a boot loader allowing the CPU to program the Flash. If the Flash is never being updated by the CPU, step 2 can be omitted. See ?Boot Loader Support - Read While Write self-programming? on page 228 for details about boot programming. Caution: An interrupt between step 5 and step 6 will make the write cycle fail, since the EEPROM Master Write Enable will time-out. If an interrupt routine accessing the EEPROM is interrupting another EEPROM access, the EEAR or EEDR regis-ter will be modified, causing the interrupted EEPROM access to fail. It is recommended to have the global interrupt flag cleared during the 4 last steps to avoid these problems. When the write access time has elapsed, the EEWE bit is cleared by hardware. The user software can poll this bit and wait for a zero before writing the next byte. When EEWE has been set, the CPU is halted for two cycles before the next instruc-tion is executed

EEMWE - EEPROM Master Write Enable

#define EEMWE_BIT 2

#define EEMWE_MASK 4

The EEMWE bit determines whether setting EEWE to one causes the EEPROM to be written. When EEMWE is written to one, writing EEWE to one within 4 clock cycles will write data to the EEPROM at the selected address. If EEMWE is zero, writing EEWE to one will have no effect. When EEMWE has been written to one by software, hardware clears the bit to zero after four clock cycles. See the description of the EEWE bit for an EEPROM write procedure.

EERIE - EEPROM Ready Interrupt Enable

#define EERIE_BIT 3

#define EERIE_MASK 8

EEPROM Ready Interrupt Enable Writing EERIE to one enables the EEPROM Ready Interrupt if the I bit in SREG is set. Writing EERIE to zero disables the interrupt. The EEPROM Ready interrupt generates a constant interrupt when EEWE is cleared.

EXTERNAL INTERRUPT

GIMSK - General Interrupt Mask Register

sfrb GIMSK = $3B;

INT2 - External Interrupt Request 2 Enable

#define INT2_BIT 5

#define INT2_MASK 32

INT0 - External Interrupt Request 0 Enable

#define INT0_BIT 6

#define INT0_MASK 64

When the INT0 bit is set (one) and the I-bit in the Status Register (SREG) is set (one), the external pin interrupt is enabled. The Interrupt Sense Control0 bits 1/0 (ISC01 and ISC00) in the MCU general Control Register (MCUCR) defines whether the external interrupt is activated on rising or falling edge of the INT0 pin or level sensed. Activity on the pin will cause an interrupt request even if INT0 is configured as an output. The corresponding interrupt of External Interrupt Request 0 is executed from program memory address $001. See also ?External Interrupts.? ? Bits 5..0 - Res: Reserved bits

INT1 - External Interrupt Request 1 Enable

#define INT1_BIT 7

#define INT1_MASK 128

When the INT1 bit is set (one) and the I-bit in the Status Register (SREG) is set (one), the external pin interrupt is enabled. The Interrupt Sense Control1 bits 1/0 (ISC11 and ISC10) in the MCU general Control Register (MCUCR) defines whether the external interrupt is activated on rising or falling edge of the INT1 pin or level sensed. Activity on the pin will cause an interrupt request even if INT1 is configured as an output. The corresponding interrupt of External Interrupt Request 1 is executed from program memory address $002. See also ?External Interrupts?.

GIFR - General Interrupt Flag Register

sfrb GIFR = $3A;

INTF2 - External Interrupt Flag 2

#define INTF2_BIT 5

#define INTF2_MASK 32

When an event on the INT2 pin triggers an interrupt request,INTF2 becomes set (one).If the I bit in SREG and the INT2 bit in GICR are set (one),the MCU will jump to the corresponding interrupt vector.The flag is cleared when the interrupt rou tine is executed.Alternatively,the flag can be cleared by writing a logical one to it.Note that when entering some sleep modes with the INT2 interrupt disabled,the input buffer on this pin will be disabled.This may cause a logic change in inter nal signals which will set the INTF2 flag

INTF0 - External Interrupt Flag 0

#define INTF0_BIT 6

#define INTF0_MASK 64

When an event on the INT0 pin triggers an interrupt request,INTF0 becomes set (one).If the I bit in SREG and the INT0 bit in GICR are set (one),the MCU will jump to the corresponding interrupt vector.The flag is cleared when the interrupt rou tine is executed.Alternatively,the flag can be cleared by writing a logical one to it.This flag is always cleared when INT0 is configured as a level interrupt.

INTF1 - External Interrupt Flag 1

#define INTF1_BIT 7

#define INTF1_MASK 128

When an event on the INT1 pin triggers an interrupt request,INTF1 becomes set (one).If the I bit in SREG and the INT1 bit in GICR are set (one),the MCU will jump to the corresponding interrupt vector.The flag is cleared when the interrupt routine is executed.Alternatively,the flag can be cleared by writing a logical one to it.This flag is always cleared when INT1 is configured as a level interrupt.

CPU

SREG - Status Register

sfrb SREG = $3F;

SPH - Stack Pointer High

sfrb SPH = $3E;

SP8 - Stack pointer bit 8

#define SP8_BIT 0

#define SP8_MASK 1

SP9 - Stack pointer bit 9

#define SP9_BIT 1

#define SP9_MASK 2

SP10 - Stack pointer bit 10

#define SP10_BIT 2

#define SP10_MASK 4

SP11 - Stack pointer bit 11

#define SP11_BIT 3

#define SP11_MASK 8

SP12

#define SP12_BIT 4

#define SP12_MASK 16

SP13 - Stack pointer bit 13

#define SP13_BIT 5

#define SP13_MASK 32

SP14 - Stack pointer bit 14

#define SP14_BIT 6

#define SP14_MASK 64

SP15 - Stack pointer bit 15

#define SP15_BIT 7

#define SP15_MASK 128

SPL - Stack Pointer Low

sfrb SPL = $3D;

SP0 - Stack pointer bit 0

#define SP0_BIT 0

#define SP0_MASK 1

SP1 - Stack pointer bit 1

#define SP1_BIT 1

#define SP1_MASK 2

SP2 - Stack pointer bit 2

#define SP2_BIT 2

#define SP2_MASK 4

SP3 - Stack pointer bit 3

#define SP3_BIT 3

#define SP3_MASK 8

SP4

#define SP4_BIT 4

#define SP4_MASK 16

SP5 - Stack pointer bit 5

#define SP5_BIT 5

#define SP5_MASK 32

SP6 - Stack pointer bit 6

#define SP6_BIT 6

#define SP6_MASK 64

SP7 - Stack pointer bit 7

#define SP7_BIT 7

#define SP7_MASK 128

MCUCR - MCU Control Register

sfrb MCUCR = $35;

ISC00 - Interrupt Sense Control 0 bit 0

#define ISC00_BIT 0

#define ISC00_MASK 1

The External Interrupt 0 is activated by the external pin INT0 if the SREG I-flag and the corresponding interrupt mask are set.The value on the INT0 pin is sampled before detecting edges.If edge or toggle interrupt is selected,pulses that last longer than one clock period will generate an interrupt.Shorter pulses are not guaranteed to generate an interrupt.If low level interrupt is selected,the low level must be held until the completion of the currently executing instruction to generate an interrupt.

ISC01 - Interrupt Sense Control 0 bit 1

#define ISC01_BIT 1

#define ISC01_MASK 2

The External Interrupt 0 is activated by the external pin INT0 if the SREG I-flag and the corresponding interrupt mask are set.The value on the INT0 pin is sampled before detecting edges.If edge or toggle interrupt is selected,pulses that last longer than one clock period will generate an interrupt.Shorter pulses are not guaranteed to generate an interrupt.If low level interrupt is selected,the low level must be held until the completion of the currently executing instruction to generate an interrupt.

ISC10 - Interrupt Sense Control 1 bit 1

#define ISC10_BIT 2

#define ISC10_MASK 4

The External Interrupt 1 is activated by the external pin INT1 if the SREG I-bit and the corresponding interrupt mask in the GICR are set.The value on the INT1 pin is sampled before detecting edges.If edge or toggle interrupt is selected,pulses that last longer than one clock period will generate an interrupt.Shorter pulses are not guaranteed to generate an interrupt.If low level interrupt is selected,the low level must be held until the completion of the currently executing instruction to generate an interrupt.

ISC11 - Interrupt Sense Control 1 bit 1

#define ISC11_BIT 3

#define ISC11_MASK 8

The External Interrupt 1 is activated by the external pin INT1 if the SREG I-bit and the corresponding interrupt mask in the GICR are set.The value on the INT1 pin is sampled before detecting edges.If edge or toggle interrupt is selected,pulses that last longer than one clock period will generate an interrupt.Shorter pulses are not guaranteed to generate an interrupt.If low level interrupt is selected,the low level must be held until the completion of the currently executing instruction to generate an interrupt.

SM1 - Sleep Mode Select

#define SM1_BIT 4

#define SM1_MASK 16

The description is to long for the tooltip help, please refer to the manual

SE - Sleep Enable

#define SE_BIT 5

#define SE_MASK 32

The SE bit must be written to logic one to make the MCU enter the sleep mode when the SLEEP instruction is executed.To avoid the MCU entering the sleep mode unless it is the programmers purpose,it is recommended to write the Sleep Enable (SE)bit to one just before the execution of the SLEEP instruction and to clear it immediately after waking up.

SRW10 - External SRAM Wait State Select

#define SRW10_BIT 6

#define SRW10_MASK 64

For a detailed description in non ATmega103 Compatibility mode, see common description for the SRWn bits below (XMRA description). In ATmega103 Compatibility mode, writing SRW10 to one enables the wait state and one extra cycle is added during read/write strobe as shown in Figure 14.

SRE - External SRAM Enable

#define SRE_BIT 7

#define SRE_MASK 128

Writing SRE to one enables the External Memory Interface.The pin functions AD7:0, A15:8, ALE, WR, and RD are acti-vated as the alternate pin functions. The SRE bit overrides any pin direction settings in the respective data direction regis-ters. Writing SRE to zero, disables the External Memory Interface and the normal pin and data direction settings are used.

MCUSR - MCU Status Register

sfrb MCUSR = $34;

PORF - Power-on reset flag

#define PORF_BIT 0

#define PORF_MASK 1

This bit is set if a power-on reset occurs. The bit is reset only by writing a logic zero to the flag. To make use of the reset flags to identify a reset condition, the user should read and then reset the MCUCSR as early as possible in the program. If the register is cleared before another reset occurs, the source of the reset can be found by examining the reset flags.

EXTRF - External Reset Flag

#define EXTRF_BIT 1

#define EXTRF_MASK 2

This bit is set if an external reset occurs. The bit is reset by a power-on reset, or by writing a logic zero to the flag.

BORF - Brown-out Reset Flag

#define BORF_BIT 2

#define BORF_MASK 4

This bit is set if a brown-out reset occurs. The bit is reset by a power-on reset, or by writing a logic zero to the flag.

WDRF - Watchdog Reset Flag

#define WDRF_BIT 3

#define WDRF_MASK 8

This bit is set if a watchdog reset occurs. The bit is reset by a power-on reset, or by writing a logic zero to the flag.

EMCUCR - Extended MCU Control Register

sfrb EMCUCR = $36;

ISC2 - Interrupt Sense Control 2

#define ISC2_BIT 0

#define ISC2_MASK 1

The asynchronous external interrupt 2 is activated by the external pin INT2 if the SREG I-bit and the corresponding interrupt mask in GICR are set.If ISC2 is written to zero,a falling edge on INT2 activates the interrupt.If ISC2 is written to one,a rising edge on INT2 activates the interrupt.Edges on INT2 are registered asynchronously.Pulses on INT2 wider than the minimum pulse given width will generate an interrupt. Shorter pulses are not guaranteed to generate an interrupt.When changing the ISC2 bit,an interrupt can occur.Therefore,it is recommended to first disable INT2 by clearing its Interrupt Enable bit in the GICR register.Then,the ISC2 bit can be changed.Finally, the INT2 interruptflag should becleared by writing a logical one to its Interrupt Flagbit (INTF2)in the GIFR register before the interrupt is re-enabled.

SRW11 - Wait State Select Bit 1 for Upper Sector

#define SRW11_BIT 1

#define SRW11_MASK 2

The SRW11 and SRW10 bits control the number of wait-states for the upper sector of the external memory address space.

SRW00 - Wait State Select Bit 0 for Lower Sector

#define SRW00_BIT 2

#define SRW00_MASK 4

The SRW00 and SRW01 bits control the number of wait-states for the upper sector of the external memory address space.

SRW01 - Wait State Select Bit 1 for Lower Sector

#define SRW01_BIT 3

#define SRW01_MASK 8

The SRW00 and SRW01 bits control the number of wait-states for the upper sector of the external memory address space.

SRL0 - Wait State Sector Limit Bit 0

#define SRL0_BIT 4

#define SRL0_MASK 16

It is possible to configure different wait-states for different external memory addresses. The external memory address space can be divided in two sectors that have separate wait-state bits.The SRL2,SRL1,and SRL0 bits select the splitting of these sectors. By default,the SRL2,SRL1,and SRL0 bits are set to zero and the entire external memory address space is treated as one sector.When the entire SRAM address space is configured as one sector,the wait-states are configured by the SRW11 and SRW10 bits.

SRL1 - Wait State Sector Limit Bit 1

#define SRL1_BIT 5

#define SRL1_MASK 32

It is possible to configure different wait-states for different external memory addresses. The external memory address space can be divided in two sectors that have separate wait-state bits.The SRL2,SRL1,and SRL0 bits select the splitting of these sectors. By default,the SRL2,SRL1,and SRL0 bits are set to zero and the entire external memory address space is treated as one sector.When the entire SRAM address space is configured as one sector,the wait-states are configured by the SRW11 and SRW10 bits.

SRL2 - Wait State Sector Limit Bit 2

#define SRL2_BIT 6

#define SRL2_MASK 64

It is possible to configure different wait-states for different external memory addresses. The external memory address space can be divided in two sectors that have separate wait-state bits.The SRL2,SRL1,and SRL0 bits select the splitting of these sectors. By default,the SRL2,SRL1,and SRL0 bits are set to zero and the entire external memory address space is treated as one sector.When the entire SRAM address space is configured as one sector,the wait-states are configured by the SRW11 and SRW10 bits.

SM0 - Sleep mode Select Bit 0

#define SM0_BIT 7

#define SM0_MASK 128

The Sleep Mode Select bits select between the five available sleep modes. See Datasheet.

SPMCR - Store Program Memory Control Register

sfrb SPMCR = $37;

SPMEN - Store Program Memory Enable

#define SPMEN_BIT 0

#define SPMEN_MASK 1

PGERS - Page Erase

#define PGERS_BIT 1

#define PGERS_MASK 2

PGWRT - Page Write

#define PGWRT_BIT 2

#define PGWRT_MASK 4

BLBSET - Boot Lock Bit Set

#define BLBSET_BIT 3

#define BLBSET_MASK 8

TIMER COUNTER 0

TCCR0 - Timer/Counter Control Register

sfrb TCCR0 = $33;

CS00 - Clock Select 1

#define CS00_BIT 0

#define CS00_MASK 1

The three clock select bits select the clock source to be used by the Timer/Counter,

CS01 - Clock Select 1

#define CS01_BIT 1

#define CS01_MASK 2

The three clock select bits select the clock source to be used by the Timer/Counter,

CS02 - Clock Select 2

#define CS02_BIT 2

#define CS02_MASK 4

The three clock select bits select the clock source to be used by the Timer/Counter,

WGM01 - Waveform Generation Mode 1

#define WGM01_BIT 3

#define WGM01_MASK 8

These bits control the counting sequence of the counter, the source for the maximum (TOP) counter value, and what type of waveform generation to be used. Modes of operation supported by the Timer/Counter unit are: Normal mode, Clear Timer on Compare match (CTC) mode, and two types of Pulse Width Modulation (PWM) modes. See Table 51 and ?Modes of Operation? on page 80.

COM00 - Compare match Output Mode 0

#define COM00_BIT 4

#define COM00_MASK 16

These bits control the output compare pin (OC0) behavior. If one or both of the COM01:0 bits are set, the OC0 output over-rides the normal port functionality of the I/O pin it is connected to. However, note that the Data Direction Register (DDR) bit corresponding to OC0 pin must be set in order to enable the output driver. When OC0 is connected to the pin, the function of the COM01:0 bits depends on the WGM01:0 bit setting. Table 52 shows the COM01:0 bit functionality when the WGM01:0 bits are set to a normal or CTC mode (non-PWM)

COM01 - Compare Match Output Mode 1

#define COM01_BIT 5

#define COM01_MASK 32

These bits control the output compare pin (OC0) behavior. If one or both of the COM01:0 bits are set, the OC0 output over-rides the normal port functionality of the I/O pin it is connected to. However, note that the Data Direction Register (DDR) bit corresponding to OC0 pin must be set in order to enable the output driver. When OC0 is connected to the pin, the function of the COM01:0 bits depends on the WGM01:0 bit setting. Table 52 shows the COM01:0 bit functionality when the WGM01:0 bits are set to a normal or CTC mode (non-PWM)

WGM00 - Waveform Generation Mode 0

#define WGM00_BIT 6

#define WGM00_MASK 64

These bits control the counting sequence of the counter, the source for the maximum (TOP) counter value, and what type of waveform generation to be used. Modes of operation supported by the Timer/Counter unit are: Normal mode, Clear Timer on Compare match (CTC) mode, and two types of Pulse Width Modulation (PWM) modes. See Table 51 and ?Modes of Operation? on page 80.

FOC0 - Force Output Compare

#define FOC0_BIT 7

#define FOC0_MASK 128

The FOC0 bit is only active when the WGM bits specifies a non-PWM mode. However, for ensuring compatibility with future devices, this bit must be set to zero when TCCR0 is written when operating in PWM mode. When writing a logical one to the FOC0 bit, an immediate compare match is forced on the waveform generation unit. The OC0 output is changed accord-ing to its COM01:0 bits setting. Note that the FOC0 bit is implemented as a strobe. Therefore it is the value present in the COM01:0 bits that determines the effect of the forced compare. A FOC0 strobe will not generate any interrupt, nor will it clear the timer in CTC mode using OCR0 as TOP. The FOC0 bit is always read as zero.

TCNT0 - Timer/Counter Register

sfrb TCNT0 = $32;

TCNT0_0

#define TCNT0_0_BIT 0

#define TCNT0_0_MASK 1

TCNT0_1

#define TCNT0_1_BIT 1

#define TCNT0_1_MASK 2

TCNT0_2

#define TCNT0_2_BIT 2

#define TCNT0_2_MASK 4

TCNT0_3

#define TCNT0_3_BIT 3

#define TCNT0_3_MASK 8

TCNT0_4

#define TCNT0_4_BIT 4

#define TCNT0_4_MASK 16

TCNT0_5

#define TCNT0_5_BIT 5

#define TCNT0_5_MASK 32

TCNT0_6

#define TCNT0_6_BIT 6

#define TCNT0_6_MASK 64

TCNT0_7

#define TCNT0_7_BIT 7

#define TCNT0_7_MASK 128

OCR0 - Output Compare Register

sfrb OCR0 = $31;

OCR0_0

#define OCR0_0_BIT 0

#define OCR0_0_MASK 1

OCR0_1

#define OCR0_1_BIT 1

#define OCR0_1_MASK 2

OCR0_2

#define OCR0_2_BIT 2

#define OCR0_2_MASK 4

OCR0_3

#define OCR0_3_BIT 3

#define OCR0_3_MASK 8

OCR0_4

#define OCR0_4_BIT 4

#define OCR0_4_MASK 16

OCR0_5

#define OCR0_5_BIT 5

#define OCR0_5_MASK 32

OCR0_6

#define OCR0_6_BIT 6

#define OCR0_6_MASK 64

OCR0_7

#define OCR0_7_BIT 7

#define OCR0_7_MASK 128

TIMSK - Timer/Counter Interrupt Mask Register

sfrb TIMSK = $39;

OCIE0 - Timer/Counter0 Output Compare Match Interrupt register

#define OCIE0_BIT 0

#define OCIE0_MASK 1

When the OCIE0 bit is written to one, and the I-bit in the Status Register is set (one), the Timer/Counter0 Compare Match interrupt is enabled. The corresponding interrupt is executed if a compare match in Timer/Counter0 occurs, i.e. when the OCF0 bit is set in the Timer/Counter Interrupt Flag Register - TIFR.

TOIE0 - Timer/Counter0 Overflow Interrupt Enable

#define TOIE0_BIT 1

#define TOIE0_MASK 2

When the TOIE0 bit is written to one, and the I-bit in the Status Register is set (one), the Timer/Counter0 Overflow interrupt is enabled. The corresponding interrupt is executed if an overflow in Timer/Counter0 occurs, i.e. when the TOV0 bit is set in the Timer/Counter Interrupt Flag Register - TIFR.

TIFR - Timer/Counter Interrupt Flag register

sfrb TIFR = $38;

OCF0 - Output Compare Flag 0

#define OCF0_BIT 0

#define OCF0_MASK 1

The OCF0 bit is set (one) when a compare match occurs between the Timer/Counter0 and the data in OCR0 - Output Compare Register0. OCF0 is cleared by hardware when executing the corresponding interrupt handling vector. Alterna-tively, OCF0 is cleared by writing a logic one to the flag. When the I-bit in SREG, OCIE0 (Timer/Counter0 Compare match Interrupt Enable), and OCF0 are set (one), the Timer/Counter0 Compare match Interrupt is executed.

TOV0 - Timer/Counter0 Overflow Flag

#define TOV0_BIT 1

#define TOV0_MASK 2

The bit TOV0 is set (one) when an overflow occurs in Timer/Counter0. TOV0 is cleared by hardware when executing the corresponding interrupt handling vector. Alternatively, TOV0 is cleared by writing a logic one to the flag. When the SREG I-bit, TOIE0 (Timer/Counter0 Overflow Interrupt Enable), and TOV0 are set (one), the Timer/Counter0 Overflow interrupt is executed. In PWM mode, this bit is set when Timer/Counter0 changes counting direction at $00.

SFIOR - Special Function IO Register

sfrb SFIOR = $30;

PSR10 - Prescaler Reset Timer/Counter1 and Timer/Counter0

#define PSR10_BIT 0

#define PSR10_MASK 1

When this bit is set (one)the Timer/Counter1 and Timer/Counter0 prescaler will be reset.The bit will be cleared by hard ware after the operation is performed.Writing a zero to this bit will have no effect.Note that Timer/Counter1 and Timer/Counter0 share the same prescaler and a reset of this prescaler will affect both timers.This bit will always be read as zero.

TIMER COUNTER 2

The 8-bit Timer/Counter2 can select clock source from CK, prescaled CK, or external crystal input TOSC1. It can also be stopped as described in the section ?Timer/Counter2 Control Register - TCCR2?. The status flags (overflow and compare match) are found in the Timer/Counter Interrupt Flag Register - TIFR. Control signals are found in the Timer/Counter Control Register TCCR2. The interrupt enable/disable settings are found in ?The Timer/Counter Interrupt Mask Register - TIMSK?. When Timer/Counter2 is externally clocked, the external signal is synchronized with the oscillator frequency of the CPU. To assure proper sampling of the external clock, the minimum time between two external clock transitions must be at least one internal CPU clock period. The external clock signal is sampled on the rising edge of the internal CPU clock. This module features a high resolution and a high accuracy usage with the lower prescaling opportunities. Similarly, the high prescaling opportunities make this unit useful for lower speed functions or exact timing functions with infrequent actions. Timer/Counter2 can also be used as an 8-bit Pulse Width Modulator. In this mode, Timer/Counter2 and the output compare register serve as a glitch-free, stand-alone PWM with centered puls

TIMSK - Timer/Counter Interrupt Mask register

sfrb TIMSK = $39;

OCIE2 - Timer/Counter2 Output Compare Match Interrupt Enable

#define OCIE2_BIT 2

#define OCIE2_MASK 4

When the OCIE2 bit is set (one) and the I-bit in the Status Register is set (one), the Timer/Counter2 Compare Match interrupt is enabled. The corresponding interrupt (at vector $006) is executed if a compare match in Timer/Counter2 occurs, i.e. when the OCF2 bit is set in the Timer/Counter Interrupt Flag Register - TIFR.

TOIE2 - Timer/Counter2 Overflow Interrupt Enable

#define TOIE2_BIT 4

#define TOIE2_MASK 16

When the TOIE2 bit is set (one) and the I-bit in the Status Register is set (one), the Timer/Counter2 Overflow interrupt is

TIFR - Timer/Counter Interrupt Flag Register

sfrb TIFR = $38;

OCF2 - Output Compare Flag 2

#define OCF2_BIT 2

#define OCF2_MASK 4

The OCF2 bit is set (one) when a compare match occurs between the Timer/Counter2 and the data in OCR2 - Output Compare Register2. OCF2 is cleared by hardware when executing the corresponding interrupt handling vector. Alternatively, OCF2 is cleared by writing a logic one to the flag. When the I-bit in SREG, and OCIE2 (Timer/Counter2 Compare match Interrupt Enable), and the OCF2 are set (one), the Timer/Counter2 Compare match Interrupt is executed.

TOV2 - Timer/Counter2 Overflow Flag

#define TOV2_BIT 4

#define TOV2_MASK 16

The TOV2 bit is set (one) when an overflow occurs in Timer/Counter2. TOV2 is cleared by hardware when executing the corresponding interrupt handling vector. Alternatively, TOV2 is cleared by writing a logic one to the flag. When the SREG I-bit, and TOIE2 (Timer/Counter2 Overflow Interrupt Enable), and TOV2 are set (one), the Timer/Counter2 Overflow interrupt is executed. In up/down PWM mode, this bit is set when Timer/Counter2 changes counting direction at $00.

TCCR2 - Timer/Counter2 Control Register

sfrb TCCR2 = $27;

CS20 - Clock Select bit 0

#define CS20_BIT 0

#define CS20_MASK 1

The Clock Select bits 2,1, and 0 define the prescaling source of Timer/Counter2. (CS22:CS21:CS20) Description. (0:0:0) Timer/Counter2 is stopped. (0:0:1) PCK2. (0:1:0) PCK2/8. (0:1:1) PCK2/32. (1:0:0) PCK2/64. (1:0:1) PCK2/128. (1:1:0) PCK2/256. (1:1:1) PCK2/1024. The Stop condition provides a Timer Enable/Disable function. The prescaled modes are scaled directly from the PCK2 clock.

CS21 - Clock Select bit 1

#define CS21_BIT 1

#define CS21_MASK 2

The Clock Select bits 2,1, and 0 define the prescaling source of Timer/Counter2. (CS22:CS21:CS20) Description. (0:0:0) Timer/Counter2 is stopped. (0:0:1) PCK2. (0:1:0) PCK2/8. (0:1:1) PCK2/32. (1:0:0) PCK2/64. (1:0:1) PCK2/128. (1:1:0) PCK2/256. (1:1:1) PCK2/1024. The Stop condition provides a Timer Enable/Disable function. The prescaled modes are scaled directly from the PCK2 clock.

CS22 - Clock Select bit 2

#define CS22_BIT 2

#define CS22_MASK 4

The Clock Select bits 2,1, and 0 define the prescaling source of Timer/Counter2. (CS22:CS21:CS20) Description. (0:0:0) Timer/Counter2 is stopped. (0:0:1) PCK2. (0:1:0) PCK2/8. (0:1:1) PCK2/32. (1:0:0) PCK2/64. (1:0:1) PCK2/128. (1:1:0) PCK2/256. (1:1:1) PCK2/1024. The Stop condition provides a Timer Enable/Disable function. The prescaled modes are scaled directly from the PCK2 clock.

CTC2 - Clear Timer/Counter2 on Compare Match

#define CTC2_BIT 3

#define CTC2_MASK 8

These bits control the counting sequence of the counter,the source for hte maximum (TOP)counter value,and what type of waveform generation to be used.Modes of operation supported by the timer/counter unit are:Normal mode (counter), Clear Timer on Compare match (CTC)mode,and two types of Pulse Width Modulation (PWM)modes. Please refer to the manual for more information.

COM20 - Compare Output Mode bit 0

#define COM20_BIT 4

#define COM20_MASK 16

The COM21 and COM20 control bits determine any output pin action following a compare match in Timer/Counter2. Output pin actions affect pin PD7(OC2). This is an alternative function to an I/O port, and the corresponding direction control bit must be set (one) to control an output pin. (COM21:COM20) description: (0:0) = Timer/Counter disconnected from output pin OC2. (0:1) = Toggle the OC2 output line. (1:0) = Clear the OC2 output line (to zero). (1:1) = Set the OC2 output line (to one). Note: In PWM mode, these bits have a different function

COM21 - Compare Output Mode bit 1

#define COM21_BIT 5

#define COM21_MASK 32

The COM21 and COM20 control bits determine any output pin action following a compare match in Timer/Counter2. Output pin actions affect pin PD7(OC2). This is an alternative function to an I/O port, and the corresponding direction control bit must be set (one) to control an output pin. (COM21:COM20) description: (0:0) = Timer/Counter disconnected from output pin OC2. (0:1) = Toggle the OC2 output line. (1:0) = Clear the OC2 output line (to zero). (1:1) = Set the OC2 output line (to one). Note: In PWM mode, these bits have a different function

PWM2 - Pulse Width Modulator Enable

#define PWM2_BIT 6

#define PWM2_MASK 64

FOC2 - Force Output Compare

#define FOC2_BIT 7

#define FOC2_MASK 128

Writing a logical one to this bit, forces a change in the compare match output pin PD7 (OC2) according to the values already set in COM21 and COM20. If the COM21 and COM20 bits are written in the same cycle as FOC2, the new settings will not take effect until next compare match or forced output compare match occurs. The Force Output Compare bit can be used to change the output pin without waiting for a compare match in the timer. The automatic action programmed in COM21 and COM20 happens as if a Compare Match had occurred, but no interrupt is generated, and the Timer/Counter will not be cleared even if CTC2 is set. The corresponding I/O pin must be set as an output pin for the FOC2 bit to have effect on the pin. The FOC2 bit will always be read as zero. Setting the FOC2 bit has no effect in PWM mode

TCNT2 - Timer/Counter2

sfrb TCNT2 = $23;

TCNT2-0 - Timer/Counter 2 bit 0

#define TCNT2-0_BIT 0

#define TCNT2-0_MASK 1

TCNT2-1 - Timer/Counter 2 bit 1

#define TCNT2-1_BIT 1

#define TCNT2-1_MASK 2

TCNT2-2 - Timer/Counter 2 bit 2

#define TCNT2-2_BIT 2

#define TCNT2-2_MASK 4

TCNT2-3 - Timer/Counter 2 bit 3

#define TCNT2-3_BIT 3

#define TCNT2-3_MASK 8

TCNT2-4 - Timer/Counter 2 bit 4

#define TCNT2-4_BIT 4

#define TCNT2-4_MASK 16

TCNT2-5 - Timer/Counter 2 bit 5

#define TCNT2-5_BIT 5

#define TCNT2-5_MASK 32

TCNT2-6 - Timer/Counter 2 bit 6

#define TCNT2-6_BIT 6

#define TCNT2-6_MASK 64

TCNT2-7 - Timer/Counter 2 bit 7

#define TCNT2-7_BIT 7

#define TCNT2-7_MASK 128

OCR2 - Timer/Counter2 Output Compare Register

sfrb OCR2 = $22;

OCR2-0 - Timer/Counter2 Output Compare Register Bit 0

#define OCR2-0_BIT 0

#define OCR2-0_MASK 1

OCR2-1 - Timer/Counter2 Output Compare Register Bit 1

#define OCR2-1_BIT 1

#define OCR2-1_MASK 2

OCR2-2 - Timer/Counter2 Output Compare Register Bit 2

#define OCR2-2_BIT 2

#define OCR2-2_MASK 4

OCR2-3 - Timer/Counter2 Output Compare Register Bit 3

#define OCR2-3_BIT 3

#define OCR2-3_MASK 8

OCR2-4 - Timer/Counter2 Output Compare Register Bit 4

#define OCR2-4_BIT 4

#define OCR2-4_MASK 16

OCR2-5 - Timer/Counter2 Output Compare Register Bit 5

#define OCR2-5_BIT 5

#define OCR2-5_MASK 32

OCR2-6 - Timer/Counter2 Output Compare Register Bit 6

#define OCR2-6_BIT 6

#define OCR2-6_MASK 64

OCR2-7 - Timer/Counter2 Output Compare Register Bit 7

#define OCR2-7_BIT 7

#define OCR2-7_MASK 128

ASSR - Asynchronous Status Register

sfrb ASSR = $26;

TCR2UB - Timer/counter Control Register2 Update Busy

#define TCR2UB_BIT 0

#define TCR2UB_MASK 1

When Timer/Counter2 operates asynchronously and TCCR2 is written, this bit becomes set (one). When TCCR2 has been updated from the temporary storage register, this bit is cleared (zero) by hardware. A logical zero in this bit indicates that TCCR2 is ready to be updated with a new value. If a write is performed to any of the three Timer/Counter2 registers while its update busy flag is set (one), the updated value might get corrupted and cause an unintentional interrupt to occur. The mechanisms for reading TCNT2, OCR2, and TCCR2 are different. When reading TCNT2, the actual timer value is read. When reading OCR2 or TCCR2, the value in the temporary storage register is rea

OCR2UB - Output Compare Register2 Update Busy

#define OCR2UB_BIT 1

#define OCR2UB_MASK 2

When Timer/Counter2 operates asynchronously and OCR2 is written, this bit becomes set (one). When OCR2 has been updated from the temporary storage register, this bit is cleared (zero) by hardware. A logical zero in this bit indicates that OCR2 is ready to be updated with a new value.

TCN2UB - Timer/Counter2 Update Busy

#define TCN2UB_BIT 2

#define TCN2UB_MASK 4

When Timer/Counter2 operates asynchronously and TCNT2 is written, this bit becomes set (one). When TCNT2 has been updated from the temporary storage register, this bit is cleared (zero) by hardware. A logical zero in this bit indicates that TCNT2 is ready to be updated with a new value.

AS2 - Asynchronous Timer/counter2

#define AS2_BIT 3

#define AS2_MASK 8

When AS2 is cleared (zero), Timer/Counter2 is clocked from the internal system clock, CK. When AS2 is set (one), Timer/Counter2 is clocked from the PC6(TOSC1) pin. Pins PC6 and PC7 are connected to a crystal oscillator and cannot be used as general I/O pins. When the value of this bit is changed, the contents of TCNT2, OCR2, and TCCR2 might be corrupted.

SFIOR - Specil Function IO Register

sfrb SFIOR = $30;

PSR2 - Prescaler Reset Timer/Counter2

#define PSR2_BIT 1

#define PSR2_MASK 2

When this bit is set (one)the Timer/Counter2 prescaler will be reset.The bit will be cleared by hardware after the operation is performed.Writing a zero to this bit will have no effect.This bit will always be read as zero if Timer/Counter2 is clocked by the internal CPU clock.If this bit is written when Timer/Counter2 is operating in asynchronous mode,the bit will remain one until the prescaler has been reset.

TIMER COUNTER 1

TIMSK - Timer/Counter Interrupt Mask Register

sfrb TIMSK = $39;

TICIE1 - Timer/Counter1 Input Capture Interrupt Enable

#define TICIE1_BIT 3

#define TICIE1_MASK 8

When the TICIE1 bit is set (one) and the I-bit in the Status Register is set (one), the Timer/Counter1 Input Capture Event Interrupt is enabled. The corresponding interrupt (at vector $003) is executed if a capture-triggering event occurs on pin 31, ICP, i.e., when the ICF1 bit is set in the Timer/Counter Interrupt Flag Register - TIFR.

OCIE1B - Timer/Counter1 Output CompareB Match Interrupt Enable

#define OCIE1B_BIT 5

#define OCIE1B_MASK 32

When the OCIE1B bit is set (one) and the I-bit in the Status Register is set (one), the Timer/Counter1 CompareB Match interrupt is enabled. The corresponding interrupt (at vector $005) is executed if a CompareB match in Timer/Counter1 occurs, i.e., when the OCF1B bit is set in the Timer/Counter Interrupt Flag Register - TIFR.

OCIE1A - Timer/Counter1 Output CompareA Match Interrupt Enable

#define OCIE1A_BIT 6

#define OCIE1A_MASK 64

When the OCIE1A bit is set (one) and the I-bit in the Status Register is set (one), the Timer/Counter1 CompareA Match interrupt is enabled. The corresponding interrupt (at vector $004) is executed if a CompareA match in Timer/Counter1 occurs, i.e., when the OCF1A bit is set in the Timer/Counter Interrupt Flag Register - TIFR.

TOIE1 - Timer/Counter1 Overflow Interrupt Enable

#define TOIE1_BIT 7

#define TOIE1_MASK 128

When the TOIE1 bit is set (one) and the I-bit in the Status Register is set (one), the Timer/Counter1 Overflow interrupt is enabled. The corresponding interrupt (at vector $006) is executed if an overflow in Timer/Counter1 occurs, i.e., when the TOV1 bit is set in the Timer/Counter Interrupt Flag Register - TIFR.

TIFR - Timer/Counter Interrupt Flag register

sfrb TIFR = $38;

ICF1 - Input Capture Flag 1

#define ICF1_BIT 3

#define ICF1_MASK 8

The ICF1 bit is set (one) to flag an input capture event, indicating that the Timer/Counter1 value has been transferred to the input capture register - ICR1. ICF1 is cleared by hardware when executing the corresponding interrupt handling vector. Alternatively, ICF1 is cleared by writing a logic one to the flag. When the SREG I-bit, and TICIE1 (Timer/Counter1 Input Capture Interrupt Enable), and ICF1 are set (one), the Timer/Counter1 Capture Interrupt is executed.

OCF1B - Output Compare Flag 1B

#define OCF1B_BIT 5

#define OCF1B_MASK 32

The OCF1B bit is set (one) when compare match occurs between the Timer/Counter1 and the data in OCR1B - Output Compare Register 1B. OCF1B is cleared by hardware when executing the corresponding interrupt handling vector. Alterna-tively, OCF1B is cleared by writing a logic one to the flag. When the I-bit in SREG, and OCIE1B (Timer/Counter1 Compare match InterruptB Enable), and the OCF1B are set (one), the Timer/Counter1 Compare B match Interrupt is executed.

OCF1A - Output Compare Flag 1A

#define OCF1A_BIT 6

#define OCF1A_MASK 64

The OCF1A bit is set (one) when compare match occurs between the Timer/Counter1 and the data in OCR1A - Output Compare Register 1A. OCF1A is cleared by hardware when executing the corresponding interrupt handling vector. Alterna-tively, OCF1A is cleared by writing a logic one to the flag. When the I-bit in SREG, and OCIE1A (Timer/Counter1 Compare match InterruptA Enable), and the OCF1A are set (one), the Timer/Counter1 Compare A match Interrupt is executed.

TOV1 - Timer/Counter1 Overflow Flag

#define TOV1_BIT 7

#define TOV1_MASK 128

The TOV1 is set (one) when an overflow occurs in Timer/Counter1. TOV1 is cleared by hardware when executing the cor-responding interrupt handling vector. Alternatively, TOV1 is cleared by writing a logic one to the flag. When the I-bit in SREG, and TOIE1 (Timer/Counter1 Overflow Interrupt Enable), and TOV1 are set (one), the Timer/Counter1 Overflow Interrupt is executed. In PWM mode, this bit is set when Timer/Counter1 changes counting direction at $0000.

TCCR1A - Timer/Counter1 Control Register A

sfrb TCCR1A = $2F;

WGM10 - Waveform Generation Mode

#define WGM10_BIT 0

#define WGM10_MASK 1

Combined with the WGM13:2 bits found in the TCCR1B register,these bits control the counting sequence of the counter, the source for maximum (TOP)counter value,and what type of waveform generation to be used.Modes of operation supported by the timer/counter unit are:Normal mode (counter),Clear Timer on Compare match (CTC)mode,and three types of Pulse Width Modulation (PWM)modes. PLease refer to the manual for a Mode Bit Description Table.

WGM11 - Waveform Generation Mode

#define WGM11_BIT 1

#define WGM11_MASK 2

Combined with the WGM13:2 bits found in the TCCR1B register,these bits control the counting sequence of the counter, the source for maximum (TOP)counter value,and what type of waveform generation to be used.Modes of operation supported by the timer/counter unit are:Normal mode (counter),Clear Timer on Compare match (CTC)mode,and three types of Pulse Width Modulation (PWM)modes. PLease refer to the manual for a Mode Bit Description Table.

FOC1B - Force Output Compare 1B

#define FOC1B_BIT 2

#define FOC1B_MASK 4

Writing a logical one to this bit, forces a change in the compare match output pin PD4 according to the values already set in COM1B1 and COM1B0.If the COM1B1 and COM1B0 bits are written in the same cycle as FOC1B,the new settings will not take effect until next compare match or forced compare match occurs. The Force Output Compare bit can be used to change the output pin without waiting for a compare match in the timer. The automatic action programmed in COM1B1 and COM1B0 happens as if a Compare Match had occurred, but no interrupt is generated. The corresponding I/O pin must be set as an output pin for the FOC1B bit to have effect on the pin. The FOC1B bit will always be read as zero. The setting of the FOC1B bit has no effect in PWM mode

FOC1A - Force Output Compare 1A

#define FOC1A_BIT 3

#define FOC1A_MASK 8

Writing a logical one to this bit, forces a change in the compare match output pin PD5 according to the values already set in COM1A1 and COM1A0.If the COM1A1 and COM1A0 bits are written in the same cycle as FOC1A,the new settings will not take effect until next compare match or forced compare match occurs. The Force Output Compare bit can be used to change the output pin without waiting for a compare match in the timer. The automatic action programmed in COM1A1 and COM1A0 happens as if a Compare Match had occurred, but no interrupt is generated and it will not clear the timer even if CTC1 in TCCR1B is set. The corresponding I/O pin must be set as an output pin for the FOC1A bit to have effect on the pin. The FOC1A bit will always be read as zero. The setting of the FOC1A bit has no effect in PWM mod

COM1B0 - Compare Output Mode 1B, bit 0

#define COM1B0_BIT 4

#define COM1B0_MASK 16

The COM1B1 and COM1B0 control bits determine any output pin action following a compare match in Timer/Counter1. Any output pin actions affect pin OC1B - Output CompareB. This is an alternative function to an I/O port, and the corre-sponding direction control bit must be set (one) to control an output pin.

COM1B1 - Compare Output Mode 1B, bit 1

#define COM1B1_BIT 5

#define COM1B1_MASK 32

The COM1B1 and COM1B0 control bits determine any output pin action following a compare match in Timer/Counter1. Any output pin actions affect pin OC1B - Output CompareB. This is an alternative function to an I/O port, and the corre-sponding direction control bit must be set (one) to control an output pin.

COM1A0 - Comparet Ouput Mode 1A, bit 0

#define COM1A0_BIT 6

#define COM1A0_MASK 64

The COM1A1 and COM1A0 control bits determine any output pin action following a compare match in Timer/Counter1. Any output pin actions affect pin OC1A - Output CompareA. This is an alternative function to an I/O port, and the corresponding direction control bit must be set (one) to control an output pin. The control configuration is shown in Table 10.

COM1A1 - Compare Output Mode 1A, bit 1

#define COM1A1_BIT 7

#define COM1A1_MASK 128

The COM1A1 and COM1A0 control bits determine any output pin action following a compare match in Timer/Counter1. Any output pin actions affect pin OC1A - Output CompareA. This is an alternative function to an I/O port, and the corresponding direction control bit must be set (one) to control an output pin. The control configuration is shown in Table 10.

TCCR1B - Timer/Counter1 Control Register B

sfrb TCCR1B = $2E;

CS10 - Prescaler source of Timer/Counter 1

#define CS10_BIT 0

#define CS10_MASK 1

Select Prescaling Clock Source of Timer/Counter1. (0:0:0) = Stop. (0:0:1) = CK. (0:1:0) = CK / 8. (0:1:1) = CK / 64. (1:0:0) = CK / 256. (1:0:1) = CK / 1024. (1:1:0) = External Pin T1, falling edge. (1:1:1) = External Pin 1, rising edge.

CS11 - Prescaler source of Timer/Counter 1

#define CS11_BIT 1

#define CS11_MASK 2

Select Prescaling Clock Source of Timer/Counter1. (0:0:0) = Stop. (0:0:1) = CK. (0:1:0) = CK / 8. (0:1:1) = CK / 64. (1:0:0) = CK / 256. (1:0:1) = CK / 1024. (1:1:0) = External Pin T1, falling edge. (1:1:1) = External Pin 1, rising edge.

CS12 - Prescaler source of Timer/Counter 1

#define CS12_BIT 2

#define CS12_MASK 4

Select Prescaling Clock Source of Timer/Counter1. (0:0:0) = Stop. (0:0:1) = CK. (0:1:0) = CK / 8. (0:1:1) = CK / 64. (1:0:0) = CK / 256. (1:0:1) = CK / 1024. (1:1:0) = External Pin T1, falling edge. (1:1:1) = External Pin 1, rising edge.

CTC1 - Clear Timer/Counter1 on Compare Match

#define CTC1_BIT 3

#define CTC1_MASK 8

ICES1 - Input Capture 1 Edge Select

#define ICES1_BIT 6

#define ICES1_MASK 64

While the ICES1 bit is cleared (zero), the Timer/Counter1 contents are transferred to the Input Capture Register - ICR1 - on the falling edge of the input capture pin - ICP. While the ICES1 bit is set (one), the Timer/Counter1 contents are transferred to the Input Capture Register - ICR1 - on the rising edge of the input capture pin - ICP.

ICNC1 - Input Capture 1 Noise Canceler

#define ICNC1_BIT 7

#define ICNC1_MASK 128

When the ICNC1 bit is cleared (zero), the input capture trigger noise canceler function is disabled. The input capture is triggered at the first rising/falling edge sampled on the ICP - input capture pin - as specified. When the ICNC1 bit is set (one), four successive samples are measures on the ICP - input capture pin, and all samples must be high/low according to the input capture trigger specification in the ICES1 bit. The actual sampling frequency is XTAL clock frequency.

TCNT1H - Timer/Counter1 High Byte

sfrb TCNT1H = $2D;

TCNT1H0 - Timer/Counter1 High Byte bit 0

#define TCNT1H0_BIT 0

#define TCNT1H0_MASK 1

TCNT1H1 - Timer/Counter1 High Byte bit 1

#define TCNT1H1_BIT 1

#define TCNT1H1_MASK 2

TCNT1H2 - Timer/Counter1 High Byte bit 2

#define TCNT1H2_BIT 2

#define TCNT1H2_MASK 4

TCNT1H3 - Timer/Counter1 High Byte bit 3

#define TCNT1H3_BIT 3

#define TCNT1H3_MASK 8

TCNT1H4 - Timer/Counter1 High Byte bit 4

#define TCNT1H4_BIT 4

#define TCNT1H4_MASK 16

TCNT1H5 - Timer/Counter1 High Byte bit 5

#define TCNT1H5_BIT 5

#define TCNT1H5_MASK 32

TCNT1H6 - Timer/Counter1 High Byte bit 6

#define TCNT1H6_BIT 6

#define TCNT1H6_MASK 64

TCNT1H7 - Timer/Counter1 High Byte bit 7

#define TCNT1H7_BIT 7

#define TCNT1H7_MASK 128

TCNT1L - Timer/Counter1 Low Byte

sfrb TCNT1L = $2C;

TCNT1L0 - Timer/Counter1 Low Byte bit 0

#define TCNT1L0_BIT 0

#define TCNT1L0_MASK 1

TCNT1L1 - Timer/Counter1 Low Byte bit 1

#define TCNT1L1_BIT 1

#define TCNT1L1_MASK 2

TCNT1L2 - Timer/Counter1 Low Byte bit 2

#define TCNT1L2_BIT 2

#define TCNT1L2_MASK 4

TCNT1L3 - Timer/Counter1 Low Byte bit 3

#define TCNT1L3_BIT 3

#define TCNT1L3_MASK 8

TCNT1L4 - Timer/Counter1 Low Byte bit 4

#define TCNT1L4_BIT 4

#define TCNT1L4_MASK 16

TCNT1L5 - Timer/Counter1 Low Byte bit 5

#define TCNT1L5_BIT 5

#define TCNT1L5_MASK 32

TCNT1L6 - Timer/Counter1 Low Byte bit 6

#define TCNT1L6_BIT 6

#define TCNT1L6_MASK 64

TCNT1L7 - Timer/Counter1 Low Byte bit 7

#define TCNT1L7_BIT 7

#define TCNT1L7_MASK 128

OCR1AH - Timer/Counter1 Outbut Compare Register High Byte

sfrb OCR1AH = $2B;

OCR1AH0 - Timer/Counter1 Outbut Compare Register High Byte bit 0

#define OCR1AH0_BIT 0

#define OCR1AH0_MASK 1

OCR1AH1 - Timer/Counter1 Outbut Compare Register High Byte bit 1

#define OCR1AH1_BIT 1

#define OCR1AH1_MASK 2

OCR1AH2 - Timer/Counter1 Outbut Compare Register High Byte bit 2

#define OCR1AH2_BIT 2

#define OCR1AH2_MASK 4

OCR1AH3 - Timer/Counter1 Outbut Compare Register High Byte bit 3

#define OCR1AH3_BIT 3

#define OCR1AH3_MASK 8

OCR1AH4 - Timer/Counter1 Outbut Compare Register High Byte bit 4

#define OCR1AH4_BIT 4

#define OCR1AH4_MASK 16

OCR1AH5 - Timer/Counter1 Outbut Compare Register High Byte bit 5

#define OCR1AH5_BIT 5

#define OCR1AH5_MASK 32

OCR1AH6 - Timer/Counter1 Outbut Compare Register High Byte bit 6

#define OCR1AH6_BIT 6

#define OCR1AH6_MASK 64

OCR1AH7 - Timer/Counter1 Outbut Compare Register High Byte bit 7

#define OCR1AH7_BIT 7

#define OCR1AH7_MASK 128

OCR1AL - Timer/Counter1 Outbut Compare Register Low Byte

sfrb OCR1AL = $2A;

OCR1AL0 - Timer/Counter1 Outbut Compare Register Low Byte Bit 0

#define OCR1AL0_BIT 0

#define OCR1AL0_MASK 1

OCR1AL1 - Timer/Counter1 Outbut Compare Register Low Byte Bit 1

#define OCR1AL1_BIT 1

#define OCR1AL1_MASK 2

OCR1AL2 - Timer/Counter1 Outbut Compare Register Low Byte Bit 2

#define OCR1AL2_BIT 2

#define OCR1AL2_MASK 4

OCR1AL3 - Timer/Counter1 Outbut Compare Register Low Byte Bit 3

#define OCR1AL3_BIT 3

#define OCR1AL3_MASK 8

OCR1AL4 - Timer/Counter1 Outbut Compare Register Low Byte Bit 4

#define OCR1AL4_BIT 4

#define OCR1AL4_MASK 16

OCR1AL5 - Timer/Counter1 Outbut Compare Register Low Byte Bit 5

#define OCR1AL5_BIT 5

#define OCR1AL5_MASK 32

OCR1AL6 - Timer/Counter1 Outbut Compare Register Low Byte Bit 6

#define OCR1AL6_BIT 6

#define OCR1AL6_MASK 64

OCR1AL7 - Timer/Counter1 Outbut Compare Register Low Byte Bit 7

#define OCR1AL7_BIT 7

#define OCR1AL7_MASK 128

OCR1BH - Timer/Counter1 Output Compare Register High Byte

sfrb OCR1BH = $29;

OCR1BH0 - Timer/Counter1 Output Compare Register High Byte bit 0

#define OCR1BH0_BIT 0

#define OCR1BH0_MASK 1

OCR1BH1 - Timer/Counter1 Output Compare Register High Byte bit 1

#define OCR1BH1_BIT 1

#define OCR1BH1_MASK 2

OCR1BH2 - Timer/Counter1 Output Compare Register High Byte bit 2

#define OCR1BH2_BIT 2

#define OCR1BH2_MASK 4

OCR1BH3 - Timer/Counter1 Output Compare Register High Byte bit 3

#define OCR1BH3_BIT 3

#define OCR1BH3_MASK 8

OCR1BH4 - Timer/Counter1 Output Compare Register High Byte bit 4

#define OCR1BH4_BIT 4

#define OCR1BH4_MASK 16

OCR1BH5 - Timer/Counter1 Output Compare Register High Byte bit 5

#define OCR1BH5_BIT 5

#define OCR1BH5_MASK 32

OCR1BH6 - Timer/Counter1 Output Compare Register High Byte bit 6

#define OCR1BH6_BIT 6

#define OCR1BH6_MASK 64

OCR1BH7 - Timer/Counter1 Output Compare Register High Byte bit 7

#define OCR1BH7_BIT 7

#define OCR1BH7_MASK 128

OCR1BL - Timer/Counter1 Output Compare Register Low Byte

sfrb OCR1BL = $28;

OCR1BL0 - Timer/Counter1 Output Compare Register Low Byte bit 0

#define OCR1BL0_BIT 0

#define OCR1BL0_MASK 1

OCR1BL1 - Timer/Counter1 Output Compare Register Low Byte bit 1

#define OCR1BL1_BIT 1

#define OCR1BL1_MASK 2

OCR1BL2 - Timer/Counter1 Output Compare Register Low Byte bit 2

#define OCR1BL2_BIT 2

#define OCR1BL2_MASK 4

OCR1BL3 - Timer/Counter1 Output Compare Register Low Byte bit 3

#define OCR1BL3_BIT 3

#define OCR1BL3_MASK 8

OCR1BL4 - Timer/Counter1 Output Compare Register Low Byte bit 4

#define OCR1BL4_BIT 4

#define OCR1BL4_MASK 16

OCR1BL5 - Timer/Counter1 Output Compare Register Low Byte bit 5

#define OCR1BL5_BIT 5

#define OCR1BL5_MASK 32

OCR1BL6 - Timer/Counter1 Output Compare Register Low Byte bit 6

#define OCR1BL6_BIT 6

#define OCR1BL6_MASK 64

OCR1BL7 - Timer/Counter1 Output Compare Register Low Byte bit 7

#define OCR1BL7_BIT 7

#define OCR1BL7_MASK 128

ICR1H - Timer/Counter1 Input Capture Register High Byte

sfrb ICR1H = $25;

ICR1H0 - Timer/Counter1 Input Capture Register High Byte bit 0

#define ICR1H0_BIT 0

#define ICR1H0_MASK 1

ICR1H1 - Timer/Counter1 Input Capture Register High Byte bit 1

#define ICR1H1_BIT 1

#define ICR1H1_MASK 2

ICR1H2 - Timer/Counter1 Input Capture Register High Byte bit 2

#define ICR1H2_BIT 2

#define ICR1H2_MASK 4

ICR1H3 - Timer/Counter1 Input Capture Register High Byte bit 3

#define ICR1H3_BIT 3

#define ICR1H3_MASK 8

ICR1H4 - Timer/Counter1 Input Capture Register High Byte bit 4

#define ICR1H4_BIT 4

#define ICR1H4_MASK 16

ICR1H5 - Timer/Counter1 Input Capture Register High Byte bit 5

#define ICR1H5_BIT 5

#define ICR1H5_MASK 32

ICR1H6 - Timer/Counter1 Input Capture Register High Byte bit 6

#define ICR1H6_BIT 6

#define ICR1H6_MASK 64

ICR1H7 - Timer/Counter1 Input Capture Register High Byte bit 7

#define ICR1H7_BIT 7

#define ICR1H7_MASK 128

ICR1L - Timer/Counter1 Input Capture Register Low Byte

sfrb ICR1L = $24;

ICR1L0 - Timer/Counter1 Input Capture Register Low Byte bit 0

#define ICR1L0_BIT 0

#define ICR1L0_MASK 1

ICR1L1 - Timer/Counter1 Input Capture Register Low Byte bit 1

#define ICR1L1_BIT 1

#define ICR1L1_MASK 2

ICR1L2 - Timer/Counter1 Input Capture Register Low Byte bit 2

#define ICR1L2_BIT 2

#define ICR1L2_MASK 4

ICR1L3 - Timer/Counter1 Input Capture Register Low Byte bit 3

#define ICR1L3_BIT 3

#define ICR1L3_MASK 8

ICR1L4 - Timer/Counter1 Input Capture Register Low Byte bit 4

#define ICR1L4_BIT 4

#define ICR1L4_MASK 16

ICR1L5 - Timer/Counter1 Input Capture Register Low Byte bit 5

#define ICR1L5_BIT 5

#define ICR1L5_MASK 32

ICR1L6 - Timer/Counter1 Input Capture Register Low Byte bit 6

#define ICR1L6_BIT 6

#define ICR1L6_MASK 64

ICR1L7 - Timer/Counter1 Input Capture Register Low Byte bit 7

#define ICR1L7_BIT 7

#define ICR1L7_MASK 128

WATCHDOG

WDTCR - Watchdog Timer Control Register

sfrb WDTCR = $21;

WDP0 - Watch Dog Timer Prescaler bit 0

#define WDP0_BIT 0

#define WDP0_MASK 1

WDP1 - Watch Dog Timer Prescaler bit 1

#define WDP1_BIT 1

#define WDP1_MASK 2

WDP2 - Watch Dog Timer Prescaler bit 2

#define WDP2_BIT 2

#define WDP2_MASK 4

WDE - Watch Dog Enable

#define WDE_BIT 3

#define WDE_MASK 8

When the WDE is set (one) the Watchdog Timer is enabled, and if the WDE is cleared (zero) the Watchdog Timer function is disabled. WDE can only be cleared if the WDTOE bit is set(one). To disable an enabled watchdog timer, the following procedure must be followed: 1. In the same operation, write a logical one to WDTOE and WDE. A logical one must be written to WDE even though it is set to one before the disable operation starts. 2. Within the next four clock cycles, write a logical 0 to WDE. This disables the watchdog

WDTOE - RW

#define WDTOE_BIT 4

#define WDTOE_MASK 16

This bit must be set (one) when the WDE bit is cleared. Otherwise, the watchdog will not be disabled. Once set, hardware will clear this bit to zero after four clock cycles. Refer to the description of the WDE bit for a watchdog disable procedure.