Manual
Table Of Contents
- Features
- 1. Pin Configurations
- 2. Overview
- 3. Disclaimer
- 4. Resources
- 5. About Code Examples
- 6. Data Retention
- 7. AVR CPU Core
- 8. Memories
- 9. System Clock and their Distribution
- 10. Power Management and Sleep Modes
- 11. System Control and Reset
- 12. Interrupts
- 13. External Interrupts
- 13.1 Pin Change Interrupt Timing
- 13.2 Register Description
- 13.2.1 EICRA – External Interrupt Control Register A
- 13.2.2 EIMSK – External Interrupt Mask Register
- 13.2.3 EIFR – External Interrupt Flag Register
- 13.2.4 PCICR – Pin Change Interrupt Control Register
- 13.2.5 PCIFR – Pin Change Interrupt Flag Register
- 13.2.6 PCMSK3 – Pin Change Mask Register 3
- 13.2.7 PCMSK2 – Pin Change Mask Register 2
- 13.2.8 PCMSK1 – Pin Change Mask Register 1
- 13.2.9 PCMSK0 – Pin Change Mask Register 0
- 14. I/O-Ports
- 14.1 Overview
- 14.2 Ports as General Digital I/O
- 14.3 Alternate Port Functions
- 14.4 Register Description
- 14.4.1 MCUCR – MCU Control Register
- 14.4.2 PORTB – Port B Data Register
- 14.4.3 DDRB – Port B Data Direction Register
- 14.4.4 PINB – Port B Input Pins Address
- 14.4.5 PORTC – Port C Data Register
- 14.4.6 DDRC – Port C Data Direction Register
- 14.4.7 PINC – Port C Input Pins Address
- 14.4.8 PORTD – Port D Data Register
- 14.4.9 DDRD – Port D Data Direction Register
- 14.4.10 PIND – Port D Input Pins Address
- 14.4.11 PORTE – Port E Data Register
- 14.4.12 DDRE – Port E Data Direction Register
- 14.4.13 PINE – Port E Input Pins Address
- 15. 8-bit Timer/Counter0 with PWM
- 15.1 Features
- 15.2 Overview
- 15.3 Timer/Counter Clock Sources
- 15.4 Counter Unit
- 15.5 Output Compare Unit
- 15.6 Compare Match Output Unit
- 15.7 Modes of Operation
- 15.8 Timer/Counter Timing Diagrams
- 15.9 Register Description
- 15.9.1 TCCR0A – Timer/Counter Control Register A
- 15.9.2 TCCR0B – Timer/Counter Control Register B
- 15.9.3 TCNT0 – Timer/Counter Register
- 15.9.4 OCR0A – Output Compare Register A
- 15.9.5 OCR0B – Output Compare Register B
- 15.9.6 TIMSK0 – Timer/Counter Interrupt Mask Register
- 15.9.7 TIFR0 – Timer/Counter 0 Interrupt Flag Register
- 16. 16-bit Timer/Counter1 with PWM
- 16.1 Features
- 16.2 Overview
- 16.3 Accessing 16-bit Registers
- 16.4 Timer/Counter Clock Sources
- 16.5 Counter Unit
- 16.6 Input Capture Unit
- 16.7 Output Compare Units
- 16.8 Compare Match Output Unit
- 16.9 Modes of Operation
- 16.10 Timer/Counter Timing Diagrams
- 16.11 Register Description
- 16.11.1 TCCR1A – Timer/Counter1 Control Register A
- 16.11.2 TCCR1B – Timer/Counter1 Control Register B
- 16.11.3 TCCR1C – Timer/Counter1 Control Register C
- 16.11.4 TCNT1H and TCNT1L – Timer/Counter1
- 16.11.5 OCR1AH and OCR1AL – Output Compare Register 1 A
- 16.11.6 OCR1BH and OCR1BL – Output Compare Register 1 B
- 16.11.7 ICR1H and ICR1L – Input Capture Register 1
- 16.11.8 TIMSK1 – Timer/Counter1 Interrupt Mask Register
- 16.11.9 TIFR1 – Timer/Counter1 Interrupt Flag Register
- 17. Timer/Counter0 and Timer/Counter1 Prescalers
- 18. PSC – Power Stage Controller
- 18.1 Features
- 18.2 Overview
- 18.3 Accessing 16-bit Registers
- 18.4 PSC Description
- 18.5 Functional Description
- 18.6 Update of Values
- 18.7 Overlap Protection
- 18.8 Signal Description
- 18.9 PSC Input
- 18.10 PSC Input Modes 001b to 10xb: Deactivate outputs without changing timing.
- 18.11 PSC Input Mode 11xb: Halt PSC and Wait for Software Action
- 18.12 Analog Synchronization
- 18.13 Interrupt Handling
- 18.14 PSC Clock Sources
- 18.15 Interrupts
- 18.16 Register Description
- 18.16.1 POC – PSC Output Configuration
- 18.16.2 PSYNC – PSC Synchro Configuration
- 18.16.3 POCRnSAH and POCRnSAL – PSC Output Compare SA Register
- 18.16.4 POCRnRAH and POCRnRAL – PSC Output Compare RA Register
- 18.16.5 POCRnSBH and POCRnSBL – PSCOutput Compare SB Register
- 18.16.6 POCRnRBH and POCRnRBL – PSC Output Compare RB Register
- 18.16.7 PCNF – PSC Configuration Register
- 18.16.8 PCTL – PSC Control Register
- 18.16.9 PMICn – PSC Module n Input Control Register
- 18.16.10 PSC Interrupt Mask Register – PIM
- 18.16.11 PIFR – PSC Interrupt Flag Register
- 19. SPI – Serial Peripheral Interface
- 20. CAN – Controller Area Network
- 20.1 Features
- 20.2 Overview
- 20.3 CAN Protocol
- 20.3.1 Principles
- 20.3.2 Message Formats
- 20.3.3 CAN Bit Timing
- 20.3.3.1 Bit Construction
- 20.3.3.2 Synchronization Segment
- 20.3.3.3 Propagation Time Segment
- 20.3.3.4 Phase Segment 1
- 20.3.3.5 Sample Point
- 20.3.3.6 Phase Segment 2
- 20.3.3.7 Information Processing Time
- 20.3.3.8 Bit Lengthening
- 20.3.3.9 Bit Shortening
- 20.3.3.10 Synchronization Jump Width
- 20.3.3.11 Programming the Sample Point
- 20.3.3.12 Synchronization
- 20.3.4 Arbitration
- 20.3.5 Errors
- 20.4 CAN Controller
- 20.5 CAN Channel
- 20.6 Message Objects
- 20.7 CAN Timer
- 20.8 Error Management
- 20.9 Interrupts
- 20.10 Register Description
- 20.10.1 CANGCON – CAN General Control Register
- 20.10.2 CANGSTA – CAN General Status Register
- 20.10.3 CANGIT – CAN General Interrupt Register
- 20.10.4 CANGIE – CAN General Interrupt Enable Register
- 20.10.5 CANEN2 and CANEN1 – CAN Enable MOb Registers
- 20.10.6 CANIE2 and CANIE1 – CAN Enable Interrupt MOb Registers
- 20.10.7 CANSIT2 and CANSIT1 – CAN Status Interrupt MOb Registers
- 20.10.8 CANBT1 – CAN Bit Timing Register 1
- 20.10.9 CANBT2 – CAN Bit Timing Register 2
- 20.10.10 CANBT3 – CAN Bit Timing Register 3
- 20.10.11 CANTCON – CAN Timer Control Register
- 20.10.12 CANTIML and CANTIMH – CAN Timer Registers
- 20.10.13 CANTTCL and CANTTCH – CAN TTC Timer Registers
- 20.10.14 CANTEC – CAN Transmit Error Counter Register
- 20.10.15 CANREC – CAN Receive Error Counter Register
- 20.10.16 CANHPMOB – CAN Highest Priority MOb Register
- 20.10.17 CANPAGE – CAN Page MOb Register
- 20.11 MOb Registers
- 20.11.1 CANSTMOB – CAN MOb Status Register
- 20.11.2 CANCDMOB – CAN MOb Control and DLC Register
- 20.11.3 CANIDT1, CANIDT2, CANIDT3, and CANIDT4 – CAN Identifier Tag Registers
- 20.11.4 CANIDM1, CANIDM2, CANIDM3, and CANIDM4 – CAN Identifier Mask Registers
- 20.11.5 CANSTML and CANSTMH – CAN Time Stamp Registers
- 20.11.6 CANMSG – CAN Data Message Register
- 20.12 Examples of CAN Baud Rate Setting
- 21. LIN / UART - Local Interconnect Network Controller or UART
- 21.1 Features
- 21.2 Overview
- 21.3 LIN Protocol
- 21.4 LIN / UART Controller
- 21.5 LIN / UART Description
- 21.5.1 Reset
- 21.5.2 Clock
- 21.5.3 LIN Protocol Selection
- 21.5.4 Configuration
- 21.5.5 Busy Signal
- 21.5.6 Bit Timing
- 21.5.7 Data Length
- 21.5.8 xxOK Flags
- 21.5.9 xxERR Flags
- 21.5.10 Frame Time Out
- 21.5.11 Break-in-data
- 21.5.12 Checksum
- 21.5.13 Interrupts
- 21.5.14 Message Filtering
- 21.5.15 Data Management
- 21.5.16 OCD Support
- 21.6 Register Description
- 21.6.1 LINCR – LIN Control Register
- 21.6.2 LINSIR – LIN Status and Interrupt Register
- 21.6.3 LINENIR – LIN Enable Interrupt Register
- 21.6.4 LINERR – LIN Error Register
- 21.6.5 LINBTR – LIN Bit Timing Register
- 21.6.6 LINBRR – LIN Baud Rate Register
- 21.6.7 LINDLR – LIN Data Length Register
- 21.6.8 LINIDR – LIN Identifier Register
- 21.6.9 LINSEL – LIN Data Buffer Selection Register
- 21.6.10 LINDAT – LIN Data Register
- 22. ADC – Analog to Digital Converter
- 22.1 Features
- 22.2 Operation
- 22.3 Starting a Conversion
- 22.4 Prescaling and Conversion Timing
- 22.5 Changing Channel or Reference Selection
- 22.6 ADC Noise Canceler
- 22.7 ADC Conversion Result
- 22.8 Temperature Measurement
- 22.9 Amplifier
- 22.10 Register Description
- 22.10.1 ADMUX – ADC Multiplexer Register
- 22.10.2 Bit 4: 0 – MUX[4:0]: ADC Channel Selection Bits
- 22.10.3 ADCSRA – ADC Control and Status Register A
- 22.10.4 ADCSRB – ADC Control and Status Register B
- 22.10.5 ADCH and ADCL – ADC Result Data Registers
- 22.10.6 DIDR0 – Digital Input Disable Register 0
- 22.10.7 DIDR1 – Digital Input Disable Register 1
- 22.10.8 AMP0CSR – Amplifier 0 Control and Status register
- 22.10.9 AMP1CSR – Amplifier 1 Control and Status register
- 22.10.10 AMP2CSR – Amplifier 2 Control and Status register
- 23. ISRC - Current Source
- 24. AC – Analog Comparator
- 24.1 Features
- 24.2 Overview
- 24.3 Use of ADC Amplifiers
- 24.4 Register Description
- 24.4.1 AC0CON – Analog Comparator 0 Control Register
- 24.4.2 AC1CON – Analog Comparator 1Control Register
- 24.4.3 AC2CON – Analog Comparator 2 Control Register
- 24.4.4 AC3CON – Analog Comparator 3 Control Register
- 24.4.5 ACSR – Analog Comparator Status Register
- 24.4.6 DIDR0 – Digital Input Disable Register 0
- 24.4.7 DIDR1 – Digital Input Disable Register 1
- 25. DAC – Digital to Analog Converter
- 26. debugWIRE On-chip Debug System
- 27. Boot Loader Support – Read-While-Write Self-Programming
- 27.1 Overview
- 27.2 Application and Boot Loader Flash Sections
- 27.3 Read-While-Write and No Read-While-Write Flash Sections
- 27.4 Boot Loader Lock Bits
- 27.5 Entering the Boot Loader Program
- 27.6 Addressing the Flash During Self-Programming
- 27.7 Self-Programming the Flash
- 27.7.1 Performing Page Erase by SPM
- 27.7.2 Filling the Temporary Buffer (Page Loading)
- 27.7.3 Performing a Page Write
- 27.7.4 Using the SPM Interrupt
- 27.7.5 Consideration While Updating BLS
- 27.7.6 Prevent Reading the RWW Section During Self-Programming
- 27.7.7 Setting the Boot Loader Lock Bits by SPM
- 27.7.8 EEPROM Write Prevents Writing to SPMCSR
- 27.7.9 Reading the Fuse and Lock Bits from Software
- 27.7.10 Reading the Signature Row from Software
- 27.7.11 Preventing Flash Corruption
- 27.7.12 Programming Time for Flash when Using SPM
- 27.7.13 Simple Assembly Code Example for a Boot Loader
- 27.7.14 ATmega16M1 - 16K - Flash Boot Loader Parameters
- 27.7.15 ATmega32M1 - 32K - Flash Boot Loader Parameters
- 27.7.16 ATmega64M1 - 64K - Flash Boot Loader Parameters
- 27.8 Register Description
- 28. Memory Programming
- 28.1 Program And Data Memory Lock Bits
- 28.2 Fuse Bits
- 28.3 PSC Output Behavior During Reset
- 28.4 Signature Bytes
- 28.5 Calibration Byte
- 28.6 Page Size
- 28.7 Parallel Programming Parameters, Pin Mapping, and Commands
- 28.8 Serial Programming Pin Mapping
- 28.9 Parallel Programming
- 28.9.1 Enter Programming Mode
- 28.9.2 Considerations for Efficient Programming
- 28.9.3 Chip Erase
- 28.9.4 Programming the Flash
- 28.9.5 Programming the EEPROM
- 28.9.6 Reading the Flash
- 28.9.7 Reading the EEPROM
- 28.9.8 Programming the Fuse Low Bits
- 28.9.9 Programming the Fuse High Bits
- 28.9.10 Programming the Extended Fuse Bits
- 28.9.11 Programming the Lock Bits
- 28.9.12 Reading the Fuse and Lock Bits
- 28.9.13 Reading the Signature Bytes
- 28.9.14 Reading the Calibration Byte
- 28.9.15 Parallel Programming Characteristics
- 28.10 Serial Downloading
- 29. Electrical Characteristics
- 30. Typical Characteristics – TBD
- 31. Register Summary
- 32. Instruction Set Summary
- 33. Errata
- 34. Ordering Information
- 35. Packaging Information
- 36. Datasheet Revision History
- Table of Contents
122
8209A–AVR–08/09
ATmega16M1/32M1/64M1
Using the ICRn Register for defining TOP works well when using fixed TOP values. By using
ICRn, the OCRnA Register is free to be used for generating a PWM output on OCnA. However,
if the base PWM frequency is actively changed by changing the TOP value, using the OCRnA as
TOP is clearly a better choice due to its double buffer feature.
In phase and frequency correct PWM mode, the compare units allow generation of PWM wave-
forms on the OCnx pins. Setting the COMnx1:0 bits to two will produce a non-inverted PWM and
an inverted PWM output can be generated by setting the COMnx1:0 to three (See Table on
page 125). The actual OCnx value will only be visible on the port pin if the data direction for the
port pin is set as output (DDR_OCnx). The PWM waveform is generated by setting (or clearing)
the OCnx Register at the compare match between OCRnx and TCNTn when the counter incre-
ments, and clearing (or setting) the OCnx Register at compare match between OCRnx and
TCNTn when the counter decrements. The PWM frequency for the output when using phase
and frequency correct PWM can be calculated by the following equation:
The N variable represents the prescaler divider (1, 8, 64, 256, or 1024).
The extreme values for the OCRnx Register represents special cases when generating a PWM
waveform output in the phase correct PWM mode. If the OCRnx is set equal to BOTTOM the
output will be continuously low and if set equal to TOP the output will be set to high for non-
inverted PWM mode. For inverted PWM the output will have the opposite logic values. If OCR1A
is used to define the TOP value (WGM13:0 = 9) and COM1A1:0 = 1, the OC1A output will toggle
with a 50% duty cycle.
16.10 Timer/Counter Timing Diagrams
The Timer/Counter is a synchronous design and the timer clock (clk
Tn
) is therefore shown as a
clock enable signal in the following figures. The figures include information on when Interrupt
Flags are set, and when the OCRnx Register is updated with the OCRnx buffer value (only for
modes utilizing double buffering). Figure 16-10 shows a timing diagram for the setting of OCFnx.
Figure 16-10. Timer/Counter Timing Diagram, Setting of OCFnx, no Prescaling
Figure 16-11 shows the same timing data, but with the prescaler enabled.
f
OCnxPFCPWM
f
clk_I/O
2 NTOP⋅⋅
----------------------------=
clk
Tn
(clk
I/O
/1)
OCFnx
clk
I/O
OCRnx
TCNTn
OCRnx Value
OCRnx - 1 OCRnx OCRnx + 1 OCRnx + 2