- •Features
- •1. Pin Configurations
- •1.1 Pin Descriptions
- •1.1.3 Port A (PA2..PA0)
- •1.1.4 Port B (PB7..PB0)
- •1.1.5 Port D (PD6..PD0)
- •1.1.6 RESET
- •1.1.7 XTAL1
- •1.1.8 XTAL2
- •2. Overview
- •2.1 Block Diagram
- •2.2 Comparison Between ATtiny2313A and ATtiny4313
- •3. About
- •3.1 Resources
- •3.2 Code Examples
- •3.3 Data Retention
- •4. CPU Core
- •4.1 Architectural Overview
- •4.2 ALU – Arithmetic Logic Unit
- •4.3 Status Register
- •4.4 General Purpose Register File
- •4.5 Stack Pointer
- •4.6 Instruction Execution Timing
- •4.7 Reset and Interrupt Handling
- •4.7.1 Interrupt Response Time
- •5. Memories
- •5.1 Program Memory (Flash)
- •5.2 Data Memory (SRAM) and Register Files
- •5.2.1 General Purpose Register File
- •5.2.2 I/O Register File
- •5.2.3 Data Memory (SRAM)
- •5.3 Data Memory (EEPROM)
- •5.3.1 Programming Methods
- •5.3.2 Read
- •5.3.3 Erase
- •5.3.4 Write
- •5.3.5 Preventing EEPROM Corruption
- •5.3.6 Program Examples
- •5.4 Register Description
- •5.4.1 EEAR – EEPROM Address Register
- •5.4.2 EEDR – EEPROM Data Register
- •5.4.3 EECR – EEPROM Control Register
- •5.4.4 GPIOR2 – General Purpose I/O Register 2
- •5.4.5 GPIOR1 – General Purpose I/O Register 1
- •5.4.6 GPIOR0 – General Purpose I/O Register 0
- •6. Clock System
- •6.1 Clock Subsystems
- •6.2 Clock Sources
- •6.2.1 Default Clock Source
- •6.2.2 External Clock
- •6.2.3 Calibrated Internal RC Oscillator
- •6.2.4 128 kHz Internal Oscillator
- •6.2.5 Crystal Oscillator
- •6.3 System Clock Prescaler
- •6.3.1 Switching Time
- •6.4 Clock Output Buffer
- •6.5 Register Description
- •6.5.1 OSCCAL – Oscillator Calibration Register
- •6.5.2 CLKPR – Clock Prescale Register
- •7. Power Management and Sleep Modes
- •7.1 Sleep Modes
- •7.1.1 Idle Mode
- •7.1.3 Standby Mode
- •7.2 Software BOD Disable
- •7.3 Power Reduction Register
- •7.4 Minimizing Power Consumption
- •7.4.1 Analog Comparator
- •7.4.2 Internal Voltage Reference
- •7.4.4 Watchdog Timer
- •7.4.5 Port Pins
- •7.5 Register Description
- •7.5.1 MCUCR – MCU Control Register
- •7.5.2 PRR – Power Reduction Register
- •8. System Control and Reset
- •8.1 Resetting the AVR
- •8.2 Reset Sources
- •8.2.2 External Reset
- •8.2.4 Watchdog Reset
- •8.3 Internal Voltage Reference
- •8.4 Watchdog Timer
- •8.4.1 Timed Sequences for Changing the Configuration of the Watchdog Timer
- •8.4.2 Code Example
- •8.5 Register Description
- •8.5.1 MCUSR – MCU Status Register
- •8.5.2 WDTCSR – Watchdog Timer Control and Status Register
- •9. Interrupts
- •9.1 Interrupt Vectors
- •9.2 External Interrupts
- •9.2.1 Low Level Interrupt
- •9.2.2 Pin Change Interrupt Timing
- •9.3 Register Description
- •9.3.1 MCUCR – MCU Control Register
- •9.3.2 GIMSK – General Interrupt Mask Register
- •9.3.3 GIFR – General Interrupt Flag Register
- •9.3.4 PCMSK2 – Pin Change Mask Register 2
- •9.3.5 PCMSK1 – Pin Change Mask Register 1
- •9.3.6 PCMSK0 – Pin Change Mask Register 0
- •10. I/O-Ports
- •10.1 Ports as General Digital I/O
- •10.1.1 Configuring the Pin
- •10.1.2 Toggling the Pin
- •10.1.3 Switching Between Input and Output
- •10.1.4 Reading the Pin Value
- •10.1.5 Digital Input Enable and Sleep Modes
- •10.1.6 Unconnected Pins
- •10.1.7 Program Examples
- •10.2 Alternate Port Functions
- •10.2.1 Alternate Functions of Port A
- •10.2.2 Alternate Functions of Port B
- •10.2.3 Alternate Functions of Port D
- •10.3 Register Description
- •10.3.1 MCUCR – MCU Control Register
- •10.3.2 PORTA – Port A Data Register
- •10.3.3 DDRA – Port A Data Direction Register
- •10.3.4 PINA – Port A Input Pins Address
- •10.3.5 PORTB – Port B Data Register
- •10.3.6 DDRB – Port B Data Direction Register
- •10.3.7 PINB – Port B Input Pins Address
- •10.3.8 PORTD – Port D Data Register
- •10.3.9 DDRD – Port D Data Direction Register
- •10.3.10 PIND – Port D Input Pins Address
- •11. 8-bit Timer/Counter0 with PWM
- •11.1 Features
- •11.2 Overview
- •11.2.1 Registers
- •11.2.2 Definitions
- •11.3 Clock Sources
- •11.4 Counter Unit
- •11.5 Output Compare Unit
- •11.5.1 Force Output Compare
- •11.5.2 Compare Match Blocking by TCNT0 Write
- •11.5.3 Using the Output Compare Unit
- •11.6 Compare Match Output Unit
- •11.6.1 Compare Output Mode and Waveform Generation
- •11.7 Modes of Operation
- •11.7.1 Normal Mode
- •11.7.2 Clear Timer on Compare Match (CTC) Mode
- •11.7.3 Fast PWM Mode
- •11.7.4 Phase Correct PWM Mode
- •11.8 Timer/Counter Timing Diagrams
- •11.9 Register Description
- •11.9.1 TCCR0A – Timer/Counter Control Register A
- •11.9.2 TCCR0B – Timer/Counter Control Register B
- •11.9.3 TCNT0 – Timer/Counter Register
- •11.9.4 OCR0A – Output Compare Register A
- •11.9.5 OCR0B – Output Compare Register B
- •11.9.6 TIMSK – Timer/Counter Interrupt Mask Register
- •11.9.7 TIFR – Timer/Counter Interrupt Flag Register
- •12. 16-bit Timer/Counter1
- •12.1 Features
- •12.2 Overview
- •12.2.1 Registers
- •12.2.2 Definitions
- •12.2.3 Compatibility
- •12.3 Timer/Counter Clock Sources
- •12.4 Counter Unit
- •12.5 Input Capture Unit
- •12.5.1 Input Capture Trigger Source
- •12.5.2 Noise Canceler
- •12.5.3 Using the Input Capture Unit
- •12.6 Output Compare Units
- •12.6.1 Force Output Compare
- •12.6.2 Compare Match Blocking by TCNT1 Write
- •12.6.3 Using the Output Compare Unit
- •12.7 Compare Match Output Unit
- •12.7.1 Compare Output Mode and Waveform Generation
- •12.8 Modes of Operation
- •12.8.1 Normal Mode
- •12.8.2 Clear Timer on Compare Match (CTC) Mode
- •12.8.3 Fast PWM Mode
- •12.8.4 Phase Correct PWM Mode
- •12.8.5 Phase and Frequency Correct PWM Mode
- •12.9 Timer/Counter Timing Diagrams
- •12.10 Accessing 16-bit Registers
- •12.10.1 Reusing the Temporary High Byte Register
- •12.11 Register Description
- •12.11.1 TCCR1A – Timer/Counter1 Control Register A
- •12.11.2 TCCR1B – Timer/Counter1 Control Register B
- •12.11.3 TCCR1C – Timer/Counter1 Control Register C
- •12.11.4 TCNT1H and TCNT1L – Timer/Counter1
- •12.11.5 OCR1AH and OCR1AL – Output Compare Register 1 A
- •12.11.6 OCR1BH and OCR1BL – Output Compare Register 1 B
- •12.11.7 ICR1H and ICR1L – Input Capture Register 1
- •12.11.8 TIMSK – Timer/Counter Interrupt Mask Register
- •12.11.9 TIFR – Timer/Counter Interrupt Flag Register
- •13. Timer/Counter0 and Timer/Counter1 Prescalers
- •13.1 Internal Clock Source
- •13.2 Prescaler Reset
- •13.3 External Clock Source
- •13.4 Register Description
- •13.4.1 GTCCR – General Timer/Counter Control Register
- •14. USART
- •14.1 Features
- •14.2 Overview
- •14.2.1 AVR USART vs. AVR UART – Compatibility
- •14.3 Clock Generation
- •14.3.1 Internal Clock Generation – The Baud Rate Generator
- •14.3.2 Double Speed Operation (U2X)
- •14.3.3 External Clock
- •14.3.4 Synchronous Clock Operation
- •14.4 Frame Formats
- •14.4.1 Parity Bit Calculation
- •14.5 USART Initialization
- •14.6 Data Transmission – The USART Transmitter
- •14.6.1 Sending Frames with 5 to 8 Data Bit
- •14.6.2 Sending Frames with 9 Data Bit
- •14.6.3 Transmitter Flags and Interrupts
- •14.6.4 Parity Generator
- •14.6.5 Disabling the Transmitter
- •14.7 Data Reception – The USART Receiver
- •14.7.1 Receiving Frames with 5 to 8 Data Bits
- •14.7.2 Receiving Frames with 9 Data Bits
- •14.7.3 Receive Compete Flag and Interrupt
- •14.7.4 Receiver Error Flags
- •14.7.5 Parity Checker
- •14.7.6 Disabling the Receiver
- •14.7.7 Flushing the Receive Buffer
- •14.8 Asynchronous Data Reception
- •14.8.1 Asynchronous Clock Recovery
- •14.8.2 Asynchronous Data Recovery
- •14.8.3 Asynchronous Operational Range
- •14.9.1 Using MPCM
- •14.10 Register Description
- •14.10.1 UDR – USART I/O Data Register
- •14.10.2 UCSRA – USART Control and Status Register A
- •14.10.3 UCSRB – USART Control and Status Register B
- •14.10.4 UCSRC – USART Control and Status Register C
- •14.10.5 UBRRL and UBRRH – USART Baud Rate Registers
- •14.11 Examples of Baud Rate Setting
- •15. USART in SPI Mode
- •15.1 Features
- •15.2 Overview
- •15.3 Clock Generation
- •15.4 SPI Data Modes and Timing
- •15.5 Frame Formats
- •15.5.1 USART MSPIM Initialization
- •15.6 Data Transfer
- •15.6.1 Transmitter and Receiver Flags and Interrupts
- •15.6.2 Disabling the Transmitter or Receiver
- •15.7 AVR USART MSPIM vs. AVR SPI
- •15.8 Register Description
- •15.8.1 UDR – USART MSPIM I/O Data Register
- •15.8.2 UCSRA – USART MSPIM Control and Status Register A
- •15.8.3 UCSRB – USART MSPIM Control and Status Register B
- •15.8.4 UCSRC – USART MSPIM Control and Status Register C
- •15.8.5 UBRRL and UBRRH – USART MSPIM Baud Rate Registers
- •16. USI – Universal Serial Interface
- •16.1 Features
- •16.2 Overview
- •16.3 Functional Descriptions
- •16.3.2 SPI Master Operation Example
- •16.3.3 SPI Slave Operation Example
- •16.3.5 Start Condition Detector
- •16.3.6 Clock speed considerations
- •16.4 Alternative USI Usage
- •16.4.4 Edge Triggered External Interrupt
- •16.4.5 Software Interrupt
- •16.5 Register Description
- •16.5.1 USICR – USI Control Register
- •16.5.2 USISR – USI Status Register
- •16.5.3 USIDR – USI Data Register
- •16.5.4 USIBR – USI Buffer Register
- •17. Analog Comparator
- •17.1 Register Description
- •17.1.1 ACSR – Analog Comparator Control and Status Register
- •17.1.2 DIDR – Digital Input Disable Register
- •18. debugWIRE On-chip Debug System
- •18.1 Features
- •18.2 Overview
- •18.3 Physical Interface
- •18.4 Software Break Points
- •18.5 Limitations of debugWIRE
- •18.6 Register Description
- •18.6.1 DWDR – debugWire Data Register
- •19. Self-Programming
- •19.1 Features
- •19.2 Overview
- •19.3 Lock Bits
- •19.4.2 Page Erase
- •19.4.3 Page Load
- •19.4.4 Page Write
- •19.4.5 SPMCSR Can Not Be Written When EEPROM is Programmed
- •19.5 Preventing Flash Corruption
- •19.6 Programming Time for Flash when Using SPM
- •19.7 Register Description
- •19.7.1 SPMCSR – Store Program Memory Control and Status Register
- •20. Lock Bits, Fuse Bits and Device Signature
- •20.1 Lock Bits
- •20.2 Fuse Bits
- •20.2.1 Latching of Fuses
- •20.3 Device Signature Imprint Table
- •20.3.1 Calibration Byte
- •20.3.2 Signature Bytes
- •20.4 Reading Lock Bits, Fuse Bits and Signature Data from Software
- •20.4.1 Lock Bit Read
- •20.4.2 Fuse Bit Read
- •20.4.3 Device Signature Imprint Table Read
- •21. External Programming
- •21.1 Memory Parametrics
- •21.2 Parallel Programming
- •21.2.1 Enter Programming Mode
- •21.2.2 Considerations for Efficient Programming
- •21.2.3 Chip Erase
- •21.2.4 Programming the Flash
- •21.2.5 Programming the EEPROM
- •21.2.6 Reading the Flash
- •21.2.7 Reading the EEPROM
- •21.2.8 Programming Low Fuse Bits
- •21.2.9 Programming High Fuse Bits
- •21.2.10 Programming Extended Fuse Bits
- •21.2.11 Programming the Lock Bits
- •21.2.12 Reading Fuse and Lock Bits
- •21.2.13 Reading Signature Bytes
- •21.2.14 Reading the Calibration Byte
- •21.3 Serial Programming
- •21.3.1 Pin Mapping
- •21.3.2 Programming Algorithm
- •21.3.3 Programming Instruction Set
- •21.4 Programming Time for Flash and EEPROM
- •22. Electrical Characteristics
- •22.1 Absolute Maximum Ratings*
- •22.2 DC Characteristics
- •22.3 Speed
- •22.4 Clock Characteristics
- •22.4.1 Calibrated Internal RC Oscillator Accuracy
- •22.4.2 External Clock Drive
- •22.5 System and Reset Characteristics
- •22.6 Analog Comparator Characteristics
- •22.7 Parallel Programming Characteristics
- •22.8 Serial Programming Characteristics
- •23. Typical Characteristics
- •23.1 Effect of Power Reduction
- •23.2 ATtiny2313A
- •23.2.1 Current Consumption in Active Mode
- •23.2.2 Current Consumption in Idle Mode
- •23.2.4 Current Consumption in Reset
- •23.2.5 Current Consumption of Peripheral Units
- •23.2.7 Output Driver Strength
- •23.2.8 Input Thresholds and Hysteresis (for I/O Ports)
- •23.2.9 BOD, Bandgap and Reset
- •23.2.10 Internal Oscillator Speed
- •23.3 ATtiny4313
- •23.3.1 Current Consumption in Active Mode
- •23.3.2 Current Consumption in Idle Mode
- •23.3.4 Current Consumption in Reset
- •23.3.5 Current Consumption of Peripheral Units
- •23.3.7 Output Driver Strength
- •23.3.8 Input Thresholds and Hysteresis (for I/O Ports)
- •23.3.9 BOD, Bandgap and Reset
- •23.3.10 Internal Oscillator Speed
- •24. Register Summary
- •25. Instruction Set Summary
- •26. Ordering Information
- •26.1 ATtiny2313A
- •26.2 ATtiny4313
- •27. Packaging Information
- •28. Errata
- •28.1 ATtiny2313A
- •28.2 ATtiny4313
- •29. Datasheet Revision History
- •Table of Contents
ATtiny2313A/4313
generation. Similarly, do not write the TCNT0 value equal to BOTTOM when the counter is down-counting.
The setup of the OC0x should be performed before setting the Data Direction Register for the port pin to output. The easiest way of setting the OC0x value is to use the Force Output Compare (FOC0x) strobe bits in Normal mode. The OC0x Registers keep their values even when changing between Waveform Generation modes.
Be aware that the COM0x1:0 bits are not double buffered together with the compare value. Changing the COM0x1:0 bits will take effect immediately.
11.6Compare Match Output Unit
The Compare Output mode (COM0x1:0) bits have two functions. The Waveform Generator uses the COM0x1:0 bits for defining the Output Compare (OC0x) state at the next Compare Match. Also, the COM0x1:0 bits control the OC0x pin output source. Figure 11-4 shows a simplified schematic of the logic affected by the COM0x1:0 bit setting. The I/O Registers, I/O bits, and I/O pins in the figure are shown in bold. Only the parts of the general I/O Port Control Registers (DDR and PORT) that are affected by the COM0x1:0 bits are shown. When referring to the OC0x state, the reference is for the internal OC0x Register, not the OC0x pin. If a system reset occur, the OC0x Register is reset to “0”.
Figure 11-4. Compare Match Output Unit, Schematic
COMnx1
COMnx0 Waveform
FOCn Generator
DATA BUS
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D Q
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The general I/O port function is overridden by the Output Compare (OC0x) from the Waveform Generator if either of the COM0x1:0 bits are set. However, the OC0x pin direction (input or output) is still controlled by the Data Direction Register (DDR) for the port pin. The Data Direction Register bit for the OC0x pin (DDR_OC0x) must be set as output before the OC0x value is visible on the pin. The port override function is independent of the Waveform Generation mode.
The design of the Output Compare pin logic allows initialization of the OC0x state before the output is enabled. Note that some COM0x1:0 bit settings are reserved for certain modes of operation. See “Register Description” on page 82.
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8246B–AVR–09/11