This documentation was generated automatically from the AVR Studio part description file ATmega163.pdf.
The 8-bit Timer/Counter0 can select clock source from CK, prescaled CK, or an external pin. In addition it can be stopped as described in ?Timer/Counter0 Control Register - TCCR0? on page 35. The overflow status flag is found in ?The Timer/Counter Interrupt Flag Register - TIFR? on page 29. Control signals are found in the Timer/Counter0 Control Register - TCCR0. The interrupt enable/disable settings for Timer/Counter0 are found in ?The Timer/Counter Interrupt Mask Regis-ter - TIMSK? on page 28. When Timer/Counter0 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. The 8-bit Timer/Counter0 features both a high resolution and a high accuracy usage with the lower prescaling opportuni-ties. Similarly, the high prescaling opportuni ties make the Timer/Counter0 useful for lower speed functions or exact timing functions with infrequent actions
sfrb TIMSK = $39;
#define TOIE0 0
When the TOIE0 bit is set (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.
sfrb TIFR = $38;
#define TOV0 0
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, and TOIE0 (Timer/Counter0 Overflow Interrupt Enable), and TOV0 are set (one), the Timer/Counter0 Overflow interrupt is executed.
sfrb TCCR0 = $33;
#define CS00 0
#define CS01 1
#define CS02 2
sfrb TCNT0 = $32;
#define TCNT00 0
#define TCNT01 1
#define TCNT02 2
#define TCNT03 3
#define TCNT04 4
#define TCNT05 5
#define TCNT06 6
#define TCNT07 7
sfrb SREG = $3F;
sfrb SPH = $3E;
#define SP8 0
#define SP9 1
#define SP10 2
sfrb SPL = $3D;
#define SP0 0
#define SP1 1
#define SP2 2
#define SP3 3
#define SP4 4
#define SP5 5
#define SP6 6
#define SP7 7
sfrb OSCCAL = $31;
#define CAL0 0
#define CAL1 1
#define CAL2 2
#define CAL3 3
#define CAL4 4
#define CAL5 5
#define CAL6 6
#define CAL7 7
sfrb MCUCR = $35;
#define ISC00 0
The External Interrupt 0 is activated by the external pin INT0 if the SREG I-flag and the corresponding interrupt mask are set. The level and edges on the external INT0 pin that activate the interrupt are defined in Table 9. 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
#define ISC01 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 level and edges on the external INT0 pin that activate the interrupt are defined in Table 9. 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
#define ISC10 2
The External Interrupt 1 is activated by the external pin INT1 if the SREG I-flag and the corresponding interrupt mask in the GIMSK are set. The level and edges on the external INT1 pin that activate the interrupt are defined in Table 8. 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
#define ISC11 3
The External Interrupt 1 is activated by the external pin INT1 if the SREG I-flag and the corresponding interrupt mask in the GIMSK are set. The level and edges on the external INT1 pin that activate the interrupt are defined in Table 8. 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
#define SM0 4
These bits select between the three available sleep modes, (0:0) = Idle. (0:1) = ADC Noise Reduction. (1:0) = Power-down. (1:1) = Power Save.
#define SM1 5
These bits select between the three available sleep modes, (0:0) = Idle. (0:1) = ADC Noise Reduction. (1:0) = Power-down. (1:1) = Power Save.
#define SE 6
The SE bit must be set (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 set the Sleep Enable SE bit just before the execution of the SLEEP instruction.
sfrb MCUSR = $34;
#define PORF 0
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.
#define EXTRF 1
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.
#define BORF 2
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.
#define WDRF 3
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.
sfrb SFIOR = $30;
#define PSR10 0
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.
#define PSR2 1
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. See ?Asynchronous Operation of Timer/Counter2? on page 49 for a detailed descrip-tion of asynchronous operation
#define PUD 2
When this bit is set (one), all pull-ups on all ports are disabled. If the bit is cleared (zero), the pull-ups can be individually enabled as described in the chapter ?I/O-Ports?.
#define ACME 3
When this bit is set (one) and the ADC is switched off (ADEN in ADCSR is zero), the ADC multiplexer selects the negative input to the Analog Comparator. When this bit is cleared (zero), AIN1 is applied to the negative input of the Analog Comparator. For a detailed description of this bit, see ?Analog Comparator Multiplexed Input?
sfrb TIMSK = $39;
#define TOIE1 2
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.
#define OCIE1B 3
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.
#define OCIE1A 4
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.
#define TICIE1 5
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.
sfrb TIFR = $38;
#define TOV1 2
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.
#define OCF1B 3
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.
#define OCF1A 4
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.
#define ICF1 5
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.
sfrb TCCR1A = $2F;
#define PWM10 0
These bits select PWM operation of Timer/Counter1 (0:0) = PWM Disabled. (0:1) = Timer/Counter1 is an 8-bit PWM. (1:0) = Timer/Counter1 is an a 9-bit PWM. (1:1) = is a 10-bit PWM.
#define PWM11 1
These bits select PWM operation of Timer/Counter1 (0:0) = PWM Disabled. (0:1) = Timer/Counter1 is an 8-bit PWM. (1:0) = Timer/Counter1 is an a 9-bit PWM. (1:1) = is a 10-bit PWM.
#define FOC1B 2
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
#define FOC1A 3
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
#define COM1B0 4
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.
#define COM1B1 5
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.
#define COM1A0 6
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.
#define COM1A1 7
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.
sfrb TCCR1B = $2E;
#define CS10 0
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.
#define CS11 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.
#define CS12 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.
#define CTC1 3
When the CTC1 control bit is set (one), the Timer/Counter1 is reset to $0000 in the clock cycle after a compareA match. If the CTC1 control bit is cleared, Timer/Counter1 continues counting and is unaffected by a compare match. When a pres-caling of 1 is used, and the compareA register is set to C, the timer will count as follows if CTC1 is set: ...|C-1|C|0|1|... When the prescaler is set to divide by 8, the timer will count like this: ...|C-1,C-1,C-1,C-1,C-1,C-1,C-1,C-1|C,C,C,C,C,C,C,C |0,0,0,0,0,0,0,0|1,1,1,1,1,1,1,1|... In PWM mode, this bit has a different function. If the CTC1 bit is cleared in PWM mode, the Timer/Counter1 acts as an up/down counter. If the CTC1 bit is set (one), the Timer/Counter wraps when it reaches the TOP value. Refer to page 41 for a detailed descriptio
#define ICES1 6
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.
#define ICNC1 7
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.
sfrb TCNT1H = $2D;
#define TCNT1H0 0
#define TCNT1H1 1
#define TCNT1H2 2
#define TCNT1H3 3
#define TCNT1H4 4
#define TCNT1H5 5
#define TCNT1H6 6
#define TCNT1H7 7
sfrb TCNT1L = $2C;
#define TCNT1L0 0
#define TCNT1L1 1
#define TCNT1L2 2
#define TCNT1L3 3
#define TCNT1L4 4
#define TCNT1L5 5
#define TCNT1L6 6
#define TCNT1L7 7
sfrb OCR1AH = $2B;
#define OCR1AH0 0
#define OCR1AH1 1
#define OCR1AH2 2
#define OCR1AH3 3
#define OCR1AH4 4
#define OCR1AH5 5
#define OCR1AH6 6
#define OCR1AH7 7
sfrb OCR1AL = $2A;
#define OCR1AL0 0
#define OCR1AL1 1
#define OCR1AL2 2
#define OCR1AL3 3
#define OCR1AL4 4
#define OCR1AL5 5
#define OCR1AL6 6
#define OCR1AL7 7
sfrb OCR1BH = $29;
#define OCR1BH0 0
#define OCR1BH1 1
#define OCR1BH2 2
#define OCR1BH3 3
#define OCR1BH4 4
#define OCR1BH5 5
#define OCR1BH6 6
#define OCR1BH7 7
sfrb OCR1BL = $28;
#define OCR1BL0 0
#define OCR1BL1 1
#define OCR1BL2 2
#define OCR1BL3 3
#define OCR1BL4 4
#define OCR1BL5 5
#define OCR1BL6 6
#define OCR1BL7 7
sfrb ICR1H = $27;
#define ICR1H0 0
#define ICR1H1 1
#define ICR1H2 2
#define ICR1H3 3
#define ICR1H4 4
#define ICR1H5 5
#define ICR1H6 6
#define ICR1H7 7
sfrb ICR1L = $26;
#define ICR1L0 0
#define ICR1L1 1
#define ICR1L2 2
#define ICR1L3 3
#define ICR1L4 4
#define ICR1L5 5
#define ICR1L6 6
#define ICR1L7 7
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
sfrb TIMSK = $39;
#define TOIE2 6
When the TOIE2 bit is set (one) and the I-bit in the Status Register is set (one), the Timer/Counter2 Overflow interrupt is
#define OCIE2 7
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.
sfrb TIFR = $38;
#define TOV2 6
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.
#define OCF2 7
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.
sfrb TCCR2 = $25;
#define CS20 0
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.
#define CS21 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.
#define CS22 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.
#define CTC2 3
When the CTC2 control bit is set (one), Timer/Counter2 is reset to $00 in the CPU clock cycle following a compare match. If the control bit is cleared, the Timer/Counter2 continues counting and is unaffected by a compare match. When a prescal-ing of 1 is used, and the compare register is set to C, the timer will count as follows if CTC2 is set: ...|C-1|C|0|1|... When the prescaler is set to divide by 8, the timer will count like this: ...|C-1,C-1,C-1,C-1,C-1,C-1,C-1,C-1|C,C,C,C,C,C,C,C |0,0,0,0,0,0,0,0|1,1,1,... In PWM mode, this bit has a different function. If the CTC2 bit is cleared in PWM mode, the Timer/Counter acts as an up/down counter. If the CTC2 bit is set (one), the Timer/Counter wraps when it reaches $FF
#define COM20 4
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.
#define COM21 5
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.
#define PWM2 6
When set (one) this bit enables PWM mode for Timer/Counter2.
#define FOC2 7
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
sfrb TCNT2 = $24;
#define TCNT2-0 0
#define TCNT2-1 1
#define TCNT2-2 2
#define TCNT2-3 3
#define TCNT2-4 4
#define TCNT2-5 5
#define TCNT2-6 6
#define TCNT2-7 7
sfrb OCR2 = $23;
#define OCR2-0 0
#define OCR2-1 1
#define OCR2-2 2
#define OCR2-3 3
#define OCR2-4 4
#define OCR2-5 5
#define OCR2-6 6
#define OCR2-7 7
sfrb ASSR = $22;
#define TCR2UB 0
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
#define OCR2UB 1
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.
#define TCN2UB 2
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.
#define AS2 3
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.
sfrb WDTCR = $21;
#define WDP0 0
#define WDP1 1
#define WDP2 2
#define WDE 3
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
#define WDTOE 4
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.
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
sfrb EEARH = $1F;
#define EEAR8 0
sfrb EEARL = $1E;
#define EEAR0 0
#define EEAR1 1
#define EEAR2 2
#define EEAR3 3
#define EEAR4 4
#define EEAR5 5
#define EEAR6 6
#define EEAR7 7
sfrb EEDR = $1D;
#define EEDR0 0
#define EEDR1 1
#define EEDR2 2
#define EEDR3 3
#define EEDR4 4
#define EEDR5 5
#define EEDR6 6
#define EEDR7 7
sfrb EECR = $1C;
#define EERE 0
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
#define EEWE 1
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
#define EEMWE 2
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.
#define EERIE 3
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.
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
sfrb SPDR = $0F;
#define SPDR0 0
#define SPDR1 1
#define SPDR2 2
#define SPDR3 3
#define SPDR4 4
#define SPDR5 5
#define SPDR6 6
#define SPDR7 7
sfrb SPSR = $0E;
#define SPI2X 0
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.
#define WCOL 6
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.
#define SPIF 7
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).
sfrb SPCR = $0D;
#define SPR0 0
#define SPR1 1
#define CPHA 2
Refer to Figure 36 or Figure 37 for the functionality of this bit.
#define CPOL 3
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.
#define MSTR 4
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.
#define DORD 5
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.
#define SPE 6
When the SPE bit is set (one), the SPI is enabled. This bit must be set to enable any SPI operations.
#define SPIE 7
This bit causes the SPI interrupt to be executed if SPIF bit in the SPSR register is set and the global interrupts are enabled.
The device features a full duplex (separate receive and transmit registers) Universal Asynchronous Receiver and Transmitter (UART). The main features are: ? Baud Rate Generator Generates any Baud Rate ? High Baud Rates at Low XTAL Frequencies ? 8 or 9 Bits Data ? Noise Filtering ? Overrun Detection ? Framing Error Detection ? False Start Bit Detection ? Three Separate Interrupts on TX Complete, TX Data Register Empty, and RX Complete ? Multi-processor Communication Mode ? Double Speed UART Mode
sfrb UDR = $0C;
#define UDR0 0
#define UDR1 1
#define UDR2 2
#define UDR3 3
#define UDR4 4
#define UDR5 5
#define UDR6 6
#define UDR7 7
sfrb UCSRA = $0B;
#define MPCM 0
This bit is used to enter Multi-Processor Communication Mode. The bit is set when the slave MCU waits for an address byte to be received. When the MCU has been addressed, the MCU switches off the MPCM bit, and starts data reception.
#define U2X 1
Setting this bit will reduce the division of the baud rate generator clock from 16 to 8, effectively doubling the transfer speed at the expense of robustness.
#define OR 3
This bit is set if an Overrun condition is detected, i.e. when a character already present in the UDR 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 UDR is read.
#define FE 4
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.
#define UDRE 5
This bit is set (one) when a character written to UDR 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 UDRIE bit in UCR is set, the UART Transmit Complete interrupt to be executed as long as UDRE is set. UDRE is cleared by writing UDR. When interrupt-driven data transmittal is used, the UART Data Register Empty Interrupt routine must write UDR in order to clear UDRE, otherwise a new interrupt will occur once the interrupt routine terminates. UDRE is set (one) during reset to indicate that the transmitter is ready
#define TXC 6
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 UDR. 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 UART 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 the bit
#define RXC 7
This bit is set (one) when a received character is transferred from the Receiver Shift register to UDR. The bit is set regard-less of any detected framing errors. When the RXCIE bit in UCR is set, the UART Receive Complete interrupt will be executed when RXC is set(one). RXC is cleared by reading UDR. When interrupt-driven data reception is used, the UART Receive Complete Interrupt routine must read UDR in order to clear RXC, otherwise a new interrupt will occur once the interrupt routine terminates.
sfrb UCSRB = $0A;
#define TXB8 0
When CHR9 is set (one), TXB8 is the 9th data bit in the character to be transmitted.
#define RXB8 1
When CHR9 is set (one), RXB8 is the 9th data bit of the received character.
#define CHR9 2
When this bit is set (one) transmitted and received characters are 9 bit long plus start and stop bits. The 9th bit is read and written by using the RXB8 and TXB8 bits in UCR, respectively. The 9th data bit can be used as an extra stop bit or a parity bit.
#define TXEN 3
This bit enables the UART transmitter when set (one). When disabling the transmitter while transmitting a character, the transmitter is not disabled before the character in the shift register plus any following character in UDR has been completely transmitted.
#define RXEN 4
This bit enables the UART receiver when set (one). When the receiver is disabled, the TXC, OR and FE status flags cannot become set. If these flags are set, turning off RXEN does not cause them to be cleared.
#define UDRIE 5
When this bit is set (one), a setting of the UDRE bit in USR will cause the UART Data Register Empty interrupt routine to be executed provided that global interrupts are enabled.
#define TXCIE 6
When this bit is set (one), a setting of the TXC bit in USR will cause the Transmit Complete interrupt routine to be executed provided that global interrupts are enabled.
#define RXCIE 7
When this bit is set (one), a setting of the RXC bit in USR will cause the Receive Complete interrupt routine to be executed provided that global interrupts are enabled.
sfrb UBRRHI = $20;
#define UBRRHI0 0
#define UBRRHI1 1
#define UBRRHI2 2
#define UBRRHI3 3
sfrb UBRR = $09;
#define UBRR0 0
#define UBRR1 1
#define UBRR2 2
#define UBRR3 3
#define UBRR4 4
#define UBRR5 5
#define UBRR6 6
#define UBRR7 7
TWI: Simple yet powerful and flexible communications interface, only two bus lines needed. Both master and slave operation supported. Device can operate as transmitter or receiver. 7-bit address space allows up to 128 different slave addresses. Multi-master arbitration support Up to 400 kHz data transfer speed Slew-rate limited output drivers Noise suppression circuitry rejects spikes on bus lines Fully programmable slave address with general call support Address recognition causes wake-up when AVR is in sleep mode The Two-Wire Serial Interface (TWI) is ideally suited to typical microcontroller applications. The TWI protocol allows the systems designer to interconnect up to 128 different devices using only two bidirectional bus lines, one for clock (SCL) andone for data (SDA). The only external hardware needed to implement the bus is a single pull-up resistor for each of the TWI bus lines. All devices connected to the bus have individual addresses, and mechanisms for resolving bus contention are inherent in the TWI protoco
sfrb TWBR = $00;
#define TWBR0 0
#define TWBR1 1
#define TWBR2 2
#define TWBR3 3
#define TWBR4 4
#define TWBR5 5
#define TWBR6 6
#define TWBR7 7
sfrb TWCR = $36;
#define TWIE 0
When this bit is written to one, and the I-bit in SREG is set, the TWI interrupt request will be activated for as long as the TWINT flag is high.
#define TWEN 2
The TWEN bit enables TWI operation and activates the TWI interface. When TWEN is written to one, the TWI takes control over the I/O pins connected to the SCL and SDA pins, enabling the slew-rate limiters and spike filters. If this bit is written to zero, the TWI is switched off and all TWI transmissions are terminated, regardless of any ongoing operation.
#define TWWC 3
The TWWC bit is set when attempting to write to the TWI Data Register - TWDR when TWINT is low. This flag is cleared by writing the TWDR register when TWINT is high.
#define TWSTO 4
Writing the TWSTO bit to one in master mode will generate a STOP condition on the 2-wire Serial Bus. When the STOP condition is executed on the bus, the TWSTO bit is cleared automatically. In slave mode, setting the TWSTO bit can be used to recover from an error condition. This will not generate a STOP condition, but the TWI returns to a well-defined unaddressed slave mode and releases the SCL and SDA lines to a high impedance state.
#define TWSTA 5
The application writes the TWSTA bit to one when it desires to become a master on the 2-wire Serial Bus. The TWI hard-ware checks if the bus is available, and generates a START condition on the bus if it is free. However, if the bus is not free, the TWI waits until a STOP condition is detected, and then generates a new START condition to claim the bus Master sta-tus. TWSTA is cleared by the TWI hardware when the START condition has been transmitted.
#define TWEA 6
The TWEA bit controls the generation of the acknowledge pulse. If the TWEA bit is written to one, the ACK pulse is gener-ated on the TWI bus if the following conditions are met: 1. The device?s own slave address has been received. 2. A general call has been received, while the TWGCE bit in the TWAR is set. 3. A data byte has been received in master receiver or slave receiver mode. By writing the TWEA bit to zero, the device can be virtually disconnected from the 2-wire Serial Bus temporarily. Address recognition can then be resumed by writing the TWEA bit to one again
#define TWINT 7
This bit is set by hardware when the TWI has finished its current job and expects application software response. If the I-bit in SREG and TWIE in TWCR are set, the MCU will jump to the TWI interrupt vector. While the TWINT flag is set, the SCL low period is stretched. The TWINT flag must be cleared by software by writing a logic one to it. Note that this flag is not automatically cleared by hardware when executing the interrupt routine. Also note that clearing this flag starts the operation of the TWI, so all accesses to the TWI Address Register (TWAR), TWI Status Register (TWSR), and TWI Data Register (TWDR) must be complete before clearing this flag
sfrb TWSR = $01;
#define TWS3 3
Bits 7..3: These 5 bits reflect the status of the TWI logic and the 2-Wire Serial Bus. The different status codes are described later in this chapter. Note that the value read from TWSR contains both the 5-bit status value and the 2-bit prescaler value. The application designer should consider masking the prescaler bits to zero when checking the Status bits. This makes status checking independent of prescaler setting. This approach is used in this datasheet, unless otherwise noted. If the prescaler setting remains unchanged in the application, the prescaler bits need not be masked. Instead, bit 1:0 in the values that TWSR is compared to can be modified to match the prescaler setting. This will yield more efficient co
#define TWS4 4
Bits 7..3: These 5 bits reflect the status of the TWI logic and the 2-Wire Serial Bus. The different status codes are described later in this chapter. Note that the value read from TWSR contains both the 5-bit status value and the 2-bit prescaler value. The application designer should consider masking the prescaler bits to zero when checking the Status bits. This makes status checking independent of prescaler setting. This approach is used in this datasheet, unless otherwise noted. If the prescaler setting remains unchanged in the application, the prescaler bits need not be masked. Instead, bit 1:0 in the values that TWSR is compared to can be modified to match the prescaler setting. This will yield more efficient co
#define TWS5 5
Bits 7..3: These 5 bits reflect the status of the TWI logic and the 2-Wire Serial Bus. The different status codes are described later in this chapter. Note that the value read from TWSR contains both the 5-bit status value and the 2-bit prescaler value. The application designer should consider masking the prescaler bits to zero when checking the Status bits. This makes status checking independent of prescaler setting. This approach is used in this datasheet, unless otherwise noted. If the prescaler setting remains unchanged in the application, the prescaler bits need not be masked. Instead, bit 1:0 in the values that TWSR is compared to can be modified to match the prescaler setting. This will yield more efficient c
#define TWS6 6
Bits 7..3: These 5 bits reflect the status of the TWI logic and the 2-Wire Serial Bus. The different status codes are described later in this chapter. Note that the value read from TWSR contains both the 5-bit status value and the 2-bit prescaler value. The application designer should consider masking the prescaler bits to zero when checking the Status bits. This makes status checking independent of prescaler setting. This approach is used in this datasheet, unless otherwise noted. If the prescaler setting remains unchanged in the application, the prescaler bits need not be masked. Instead, bit 1:0 in the values that TWSR is compared to can be modified to match the prescaler setting. This will yield more efficient co
#define TWS7 7
Bits 7..3: These 5 bits reflect the status of the TWI logic and the 2-Wire Serial Bus. The different status codes are described later in this chapter. Note that the value read from TWSR contains both the 5-bit status value and the 2-bit prescaler value. The application designer should consider masking the prescaler bits to zero when checking the Status bits. This makes status checking independent of prescaler setting. This approach is used in this datasheet, unless otherwise noted. If the prescaler setting remains unchanged in the application, the prescaler bits need not be masked. Instead, bit 1:0 in the values that TWSR is compared to can be modified to match the prescaler setting. This will yield more efficient c
sfrb TWDR = $03;
#define TWD0 0
#define TWD1 1
#define TWD2 2
#define TWD3 3
#define TWD4 4
#define TWD5 5
#define TWD6 6
#define TWD7 7
sfrb TWAR = $02;
#define TWGCE 0
#define TWA0 1
#define TWA1 2
#define TWA2 3
#define TWA3 4
#define TWA4 5
#define TWA5 6
#define TWA6 7
sfrb PORTA = $1B;
#define PORTA0 0
#define PORTA1 1
#define PORTA2 2
#define PORTA3 3
#define PORTA4 4
#define PORTA5 5
#define PORTA6 6
#define PORTA7 7
sfrb DDRA = $1A;
#define DDA0 0
#define DDA1 1
#define DDA2 2
#define DDA3 3
#define DDA4 4
#define DDA5 5
#define DDA6 6
#define DDA7 7
sfrb PINA = $19;
#define PINA0 0
#define PINA1 1
#define PINA2 2
#define PINA3 3
#define PINA4 4
#define PINA5 5
#define PINA6 6
#define PINA7 7
sfrb PORTB = $18;
#define PORTB0 0
#define PORTB1 1
#define PORTB2 2
#define PORTB3 3
#define PORTB4 4
#define PORTB5 5
#define PORTB6 6
#define PORTB7 7
sfrb DDRB = $17;
#define DDB0 0
#define DDB1 1
#define DDB2 2
#define DDB3 3
#define DDB4 4
#define DDB5 5
#define DDB6 6
#define DDB7 7
sfrb PINB = $16;
#define PINB0 0
#define PINB1 1
#define PINB2 2
#define PINB3 3
#define PINB4 4
#define PINB5 5
#define PINB6 6
#define PINB7 7
sfrb PORTC = $15;
#define PORTC0 0
#define PORTC1 1
#define PORTC2 2
#define PORTC3 3
#define PORTC4 4
#define PORTC5 5
#define PORTC6 6
#define PORTC7 7
sfrb DDRC = $14;
#define DDC0 0
#define DDC1 1
#define DDC2 2
#define DDC3 3
#define DDC4 4
#define DDC5 5
#define DDC6 6
#define DDC7 7
sfrb PINC = $13;
#define PINC0 0
#define PINC1 1
#define PINC2 2
#define PINC3 3
#define PINC4 4
#define PINC5 5
#define PINC6 6
#define PINC7 7
sfrb PORTD = $12;
#define PORTD0 0
#define PORTD1 1
#define PORTD2 2
#define PORTD3 3
#define PORTD4 4
#define PORTD5 5
#define PORTD6 6
#define PORTD7 7
sfrb DDRD = $11;
#define DDD0 0
#define DDD1 1
#define DDD2 2
#define DDD3 3
#define DDD4 4
#define DDD5 5
#define DDD6 6
#define DDD7 7
sfrb PIND = $10;
#define PIND0 0
#define PIND1 1
#define PIND2 2
#define PIND3 3
#define PIND4 4
#define PIND5 5
#define PIND6 6
#define PIND7 7
sfrb SFIOR = $30;
#define ACME 3
When this bit is written logic one and the ADC is switched off (ADEN in ADCSR is zero), the ADC multiplexer selects the negative input to the Analog Comparator. When this bit is written logic zero, AIN1 is applied to the negative input of the Analog Comparator. For a detailed description of this bit, see ?Analog Comparator Multiplexed Input? on page 186.
sfrb ACSR = $08;
#define ACIS0 0
These bits determine which comparator events that trigger the Analog Comparator interrupt.
#define ACIS1 1
These bits determine which comparator events that trigger the Analog Comparator interrupt.
#define ACIC 2
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
#define ACIE 3
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.
#define ACI 4
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.
#define ACO 5
The output of the analog comparator is synchronized and then directly connected to ACO. The synchronization introduces a delay of 1-2 clock cycles.
#define ACBG 6
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.
#define ACD 7
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.
AD Converter Feature list: 10-bit Resolution. 0.5 LSB Integral Non-Linearity. +-2 LSB Absolute Accuracy. TBD - 260 µs Conversion Time. Up to TBD kSPS at maximum resolution. 8 Multiplexed Single Ended Input Channels. 7 Differential input channels (TQFP package only). 2 Differential input channels with optional gain of 10x and 200x (TQFP package only). Optional left adjustment for ADC result readout. 0 - VCC ADC Input Voltage Range. Selectable 2.56 V ADC reference voltage. Free Running or Single Conversion Mode. Interrupt on ADC Conversion Complete. Sleep Mode Noise
sfrb ADMUX = $07;
#define MUX0 0
The value of these bits selects which combination of analog inputs are connected to the ADC. These bits also select the gain for the differential channels. See Table 92 for details. If these bits are changed during a conversion, the change will not go in effect until this conversion is complete (ADIF in ADCSR is set).
#define MUX1 1
The value of these bits selects which combination of analog inputs are connected to the ADC. These bits also select the gain for the differential channels. See Table 92 for details. If these bits are changed during a conversion, the change will not go in effect until this conversion is complete (ADIF in ADCSR is set).
#define MUX2 2
The value of these bits selects which combination of analog inputs are connected to the ADC. These bits also select the gain for the differential channels. See Table 92 for details. If these bits are changed during a conversion, the change will not go in effect until this conversion is complete (ADIF in ADCSR is set).
#define MUX3 3
The value of these bits selects which combination of analog inputs are connected to the ADC. These bits also select the gain for the differential channels. See Table 92 for details. If these bits are changed during a conversion, the change will not go in effect until this conversion is complete (ADIF in ADCSR is set).
#define MUX4 4
The value of these bits selects which combination of analog inputs are connected to the ADC. These bits also select the gain for the differential channels. See Table 92 for details. If these bits are changed during a conversion, the change will not go in effect until this conversion is complete (ADIF in ADCSR is set).
#define ADLAR 5
The ADLAR bit affects the presentation of the ADC conversion result in the ADC data register. If ADLAR is cleared, the result is right adjusted. If ADLAR is set, the result is left adjusted. Changing the ADLAR bit will affect the ADC data register immediately, regardless of any ongoing conversions. For a complete description of this bit, see ?The ADC Data Register -ADCL and ADCH? on page 198.
#define REFS0 6
These bits select the voltage reference for the ADC, as shown in Table 91. If these bits are changed during a conversion, the change will not go in effect until this conversion is complete (ADIF in ADCSR is set). If differential channels are used, the selected reference should not be closer to AV CC than indicated in Table 94 on page 200. The internal voltage reference options may not be used if an external reference voltage is being applied to the AREF pin.
#define REFS1 7
These bits select the voltage reference for the ADC, as shown in Table 91. If these bits are changed during a conversion, the change will not go in effect until this conversion is complete (ADIF in ADCSR is set). If differential channels are used, the selected reference should not be closer to AV CC than indicated in Table 94 on page 200. The internal voltage reference options may not be used if an external reference voltage is being applied to the AREF pin.
sfrb ADCSRA = $06;
#define ADPS0 0
These bits determine the division factor between the XTAL frequency and the input clock to the ADC.
#define ADPS1 1
These bits determine the division factor between the XTAL frequency and the input clock to the ADC.
#define ADPS2 2
These bits determine the division factor between the XTAL frequency and the input clock to the ADC.
#define ADIE 3
When this bit is set (one) and the I-bit in SREG is set (one), the ADC Conversion Complete Interrupt is activated.
#define ADIF 4
This bit is set (one) when an ADC conversion completes and the data registers are updated. The ADC Conversion Complete Interrupt is executed if the ADIE bit and the I-bit in SREG are set (one). ADIF is cleared by hardware when executing the corresponding interrupt handling vector. Alternatively, ADIF is cleared by writing a logical one to the flag. Beware that if doing a read-modify-write on ADCSR, a pending interrupt can be disabled. This also applies if the SBI and CBI instructions are used.
#define ADFR 5
When this bit is set (one) the ADC operates in Free Running Mode. In this mode, the ADC samples and updates the data registers continuously. Clearing this bit (zero) will terminate Free Running Mode.
#define ADSC 6
In Single Conversion Mode, a logical ?1? must be written to this bit to start each conversion. In Free Running Mode, a logical ?1? must be written to this bit to start the first conversion. The first time ADSC has been written after the ADC has been enabled, or if ADSC is written at the same time as the ADC is enabled, an extended conversion will result. This extended conversion performs initialization of the ADC. ADSC will read as one as long as a conversion is in progress. When the conversion is complete, it returns to zero. When a dummy conversion precedes a real conversion, ADSC will stay high until the real conversion completes. Writing a 0 to this bit has no effect
#define ADEN 7
Writing a logical ?1? to this bit enables the ADC. By clearing this bit to zero, the ADC is turned off. Turning the ADC off while a conversion is in progress, will terminate this conversion.
sfrb ADCH = $05;
#define ADCH0 0
#define ADCH1 1
#define ADCH2 2
#define ADCH3 3
#define ADCH4 4
#define ADCH5 5
#define ADCH6 6
#define ADCH7 7
sfrb ADCL = $04;
#define ADCL0 0
#define ADCL1 1
#define ADCL2 2
#define ADCL3 3
#define ADCL4 4
#define ADCL5 5
#define ADCL6 6
#define ADCL7 7
sfrb GIMSK = $3B;
#define INT0 6
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
#define INT1 7
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?.
sfrb GIFR = $3A;
#define INTF0 6
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 GIMSK are set (one), the MCU will jump to the interrupt vector at address $001. The flag is cleared when the interrupt routine is executed. Alternatively, the flag can be cleared by writing a logical one to it.
#define INTF1 7
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 GIMSK are set (one), the MCU will jump to the interrupt vector at address $002. The flag is cleared when the interrupt routine is executed. Alternatively, the flag can be cleared by writing a logical one to it.
The Boot Loader Support provides a mechanism for downloading and uploading program code by the MCU itself. This feature allows flexible application software updates controlled by the MCU using a Flash-resident Boot Loader program. The Boot Loader program can use any available data interface and associated proto-col to read code and write (program) that code into the Flash memory, or read the code from the program memory. The program code within the Boot Loader section has the capability to write into the entire Flash, including the Boot Loader Memory. The Boot Loader can thus even modify itself, and it can also erase itself from the code if the feature is not needed anymore. The size of the Boot Loader Memory is configurable with fuses and the Boot Loader has two separate sets of Boot Lock Bits which can be set independently. This gives the user a unique flexibility to select different levels of protection.
sfrb SPMCR = $37;
#define SPMEN 0
This bit enables the SPM instruction for the next four clock cycles. If written to one together with either RWWSRE, BLB-SET, PGWRT or PGERS, the following SPM instruction will have a special meaning, see description above. If only SPMEN is written, the following SPM instruction will store the value in R1:R0 in the temporary page buffer addressed by the Z pointer. The LSB of the Z pointer is ignored. The SPMEN bit will auto-clear upon completion of an SPM instruction, or if no SPM instruction is executed within four clock cycles. During page erase and page write, the SPMEN bit remain high until the operation is completed. Writing any other combination than ?10001?, "01001", "00101", "00011" or "00001" in the lower five bits will have no e
#define PGERS 1
If this bit is written to one at the same time as SPMEN, the next SPM instruction within four clock cycles executes page erase. The page address is taken from the high part of the Z pointer. The data in R1 and R0 are ignored. The PGERS bit will auto-clear upon completion of a page erase, or if no SPM instruction is executed within four clock cycles. The CPU is halted during the entire page write operation if the NRWW section is addressed.
#define PGWRT 2
If this bit is written to one at the same time as SPMEN, the next SPM instruction within four clock cycles executes page write, with the data stored in the temporary buffer. The page address is taken from the high part of the Z pointer. The data in R1 and R0 are ignored. The PGWRT bit will auto-clear upon completion of a page write, or if no SPM instruction is exe-cuted within four clock cycles. The CPU is halted during the entire page write operation if the NRWW section is addressed.
#define BLBSET 3
If this bit is written to one at the same time as SPMEN, the next SPM instruction within four clock cycles sets Boot Lock bits, according to the data in R0. The data in R1 and the address in the Z pointer are ignored. The BLBSET bit will automatically be cleared upon completion of the lock bit set, or if no SPM instruction is executed within four clock cycles. An LPM instruction within three cycles after BLBSET and SPMEN are set in the SPMCR register, will read either the Lock-bits or the Fuse bits (depending on Z0 in the Z pointer) into the destination register. See ?Reading the Fuse and Lock Bits from Software? on page 235 for det
#define ASRE 4
Application section read enable
#define ASB 6
Application section busy