This documentation was generated automatically from the AVR Studio part description file ATtiny15.pdf.
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 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 ADCSR = $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 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 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.
sfrb EEAR = $1E;
#define EEAR0 0
#define EEAR1 1
#define EEAR2 2
#define EEAR3 3
#define EEAR4 4
#define EEAR5 5
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 set. When the EERE bit is cleared (zero) by hardware, requested data is found in the EEDR register. The EEPROM read access takes one instruction and there is no need to poll the EERE bit. When EERE has been set, 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 when new data or address is written to the EEPROM I/O registers, the write operation will be interrupted, and the result is undefined.
#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 2 and 3 is unessential): 1. Wait until EEWE becomes zero. 2. Write new EEPROM address to EEARL and EEARH (optional). 3. Write new EEPROM data to EEDR (optional). 4. Write a logical one to the EEMWE bit in EECR (to be able to write a logical one to the EEMWE bit, the EEWE bit mustbewritten to zero in thesamecycle). 5. Within four clock cycles after setting EEMWE, write a logical one to EEWE. When the write access time (typically 2.5 ms at V CC =5Vor 4msatV CC = 2.7V) has elapsed, the EEWE bit is cleared (zero) 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 or two cycles before the next instruction is executed. Caution: An interrupt between step 4 and step 5 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.
#define EEMWE 2
The EEMWE bit determines whether setting EEWE to one causes the EEPROM to be written. When EEMWE is set(one) setting EEWE will write data to the EEPROM at the selected address If EEMWE is zero, setting EEWE will have no effect. When EEMWE has been set (one) by software, hardware clears the bit to zero after four clock cycles. See the description of the EEWE bit for a EEPROM write procedure.
#define EERIE 3
When the I-bit in SREG and EERIE are set (one), the EEPROM Ready Interrupt is enabled. When cleared (zero), the interrupt is disabled. The EEPROM Ready Interrupt generates a constant interrupt when EEWE is cleared (zero).
sfrb PORTB = $18;
#define PORTB0 0
#define PORTB1 1
#define PORTB2 2
#define PORTB3 3
#define PORTB4 4
sfrb DDRB = $17;
#define DDB0 0
#define DDB1 1
#define DDB2 2
#define DDB3 3
#define DDB4 4
#define DDB5 5
sfrb PINB = $16;
#define PINB0 0
#define PINB1 1
#define PINB2 2
#define PINB3 3
#define PINB4 4
#define PINB5 5
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 1
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 1
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 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.
sfrb SREG = $3F;
sfrb MCUCR = $35;
#define ISC00 0
#define ISC01 1
#define SM0 3
#define SM1 4
#define SE 5
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.
#define PUD 6
sfrb MCUSR = $34;
#define PORF 0
This bit is set by a power-on reset. A watchdog reset or an external reset will leave this bit unchanged
#define EXTRF 1
After a power-on reset, this bit is undefined (X). It will be set by an external reset. A watchdog reset will leave this bit unchanged.
#define BORF 2
#define WDRF 3
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 GIMSK = $3B;
#define PCIE 5
#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
sfrb GIFR = $3A;
#define PCIF 5
#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.
sfrb TCCR1 = $30;
#define CS10 0
The Clock Select bits 3, 2, 1, and 0 define the prescaling source of Timer/Counter1.
#define CS11 1
The Clock Select bits 3, 2, 1, and 0 define the prescaling source of Timer/Counter1.
#define CS12 2
The Clock Select bits 3, 2, 1, and 0 define the prescaling source of Timer/Counter1.
#define CS13 3
The Clock Select bits 3, 2, 1, and 0 define the prescaling source of Timer/Counter1.
#define COM1A0 4
The COM1A1 and COM1A0 control bits determine any output pin action following a compare match A in Timer/Counter1. Output pin actions affect pin PB1(OC1A). Since this is an alternative function to an I/O port, the corresponding direction control bit must be set (one) to control an output pin.
#define COM1A1 5
The COM1A1 and COM1A0 control bits determine any output pin action following a compare match A in Timer/Counter1. Output pin actions affect pin PB1(OC1A). Since this is an alternative function to an I/O port, the corresponding direction control bit must be set (one) to control an output pin.
#define PWM1 6
When set (one), this bit enables PWM mode for Timer/Counter1.
#define CTC1 7
When the CTC1 control bit is set (one), Timer/Counter1 is reset to $00 in the CPU clock cycle after a compare match with OCR1A register value. If the control bit is cleared, Timer/Counter1 continues counting and is unaffected by a compare match.
sfrb TCNT1 = $2F;
#define TCNT1_0 0
#define TCNT1_1 1
#define TCNT1_2 2
#define TCNT1_3 3
#define TCNT1_4 4
#define TCNT1_5 5
#define TCNT1_6 6
#define TCNT1_7 7
sfrb OCR1A = $2E;
#define OCR1A0 0
#define OCR1A1 1
#define OCR1A2 2
#define OCR1A3 3
#define OCR1A4 4
#define OCR1A5 5
#define OCR1A6 6
#define OCR1A7 7
sfrb OCR1B = $2D;
#define OCR1B0 0
#define OCR1B1 1
#define OCR1B2 2
#define OCR1B3 3
#define OCR1B4 4
#define OCR1B5 5
#define OCR1B6 6
#define OCR1B7 7
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 $004) 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 OCIE1A 6
When the OCIE1A bit is set (one) and the I-bit in the Status Register is set (one), the Timer/Counter1 Compare Match, interrupt is enabled. The corresponding interrupt (at vector $003) is executed if a compare match A in Timer/Counter1 occurs, i.e., when the OCF1A bit is set (one) in the Timer/Counter Interrupt Flag Register (TIFR).
sfrb TIFR = $38;
#define TOV1 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 logical ?1? to the flag. When the SREG I-bit, TOIE0 (Timer/Counter0 Overf low Interrupt Enable) and TOV0 are set (one), the Timer/Counter0 Overflow interrupt is executed.
#define OCF1A 6
The OCF1A bit is set (one) when compare match occurs between Timer/Counter1 and the data value in OCR1A (Output Compare Register 1A). OCF1A is cleared by hard-ware when executing the corresponding interrupt handling vector. Alternatively, OCF1A is cleared by writing a logical ?1? to the flag. When the I-bit in SREG, OCIE1A, and OCF1A are set (one), the Timer/Counter1 compare match A interrupt is executed.
sfrb SFIOR = $2C;
#define PSR0 0
When this bit is set (one) the Timer/Counter0 prescaler will be reset. The bit will be cleared by hardware after the operation is performed. Writing a ?0? to this bit will have no effect. This bit will always be read as zero.
#define PSR1 1
When this bit is set (one) the Timer/Counter1 prescaler will be reset. The bit will be cleared by hardware after the operation is performed. Writing a ?0? to this bit will have no effect. This bit will always be read as zero.
#define FOC1A 2
Writing a logical ?1? to this bit forces a change in the compare match output pin PB1 (OC1A) according to the values already set in COM1A1 and COM1A0. The Force Output Compare bit can be used to change the output pin without waiting for a compare match in timer. The automatic action programmed in COM1A1 and COM1A0 happens as if a Compare Match had occurred, but no interrupt is generated and the Timer/Counter1 will not be cleared even if CTC1 is set. The FOC1A bit will always be read as zero. The setting of the FOC1A bit has no effect in PWM mode