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

69
8209A–AVR–08/09
ATmega16M1/32M1/64M1
values are read back again, but as previously discussed, a nop instruction is included to be able
to read back the value recently assigned to some of the pins.
Note: 1. For the assembly program, two temporary registers are used to minimize the time from pull-
ups are set on pins 0, 1, 6, and 7, until the direction bits are correctly set, defining bit 2 and 3
as low and redefining bits 0 and 1 as strong high drivers.
14.2.5 Digital Input Enable and Sleep Modes
As shown in Figure 14-2, the digital input signal can be clamped to ground at the input of the
schmitt-trigger. The signal denoted SLEEP in the figure, is set by the MCU Sleep Controller in
Power-down mode, Power-save mode, and Standby mode to avoid high power consumption if
some input signals are left floating, or have an analog signal level close to V
CC
/2.
SLEEP is overridden for port pins enabled as external interrupt pins. If the external interrupt
request is not enabled, SLEEP is active also for these pins. SLEEP is also overridden by various
other alternate functions as described in “Alternate Port Functions” on page 70.
If a logic high level (“one”) is present on an Asynchronous External Interrupt pin configured as
“Interrupt on Rising Edge, Falling Edge, or Any Logic Change on Pin” while the external interrupt
is not enabled, the corresponding External Interrupt Flag will be set when resuming from the
above mentioned sleep modes, as the clamping in these sleep modes produces the requested
logic change.
Assembly Code Example
(1)
...
; Define pull-ups and set outputs high
; Define directions for port pins
ldi r16, (1<<PB7)|(1<<PB6)|(1<<PB1)|(1<<PB0)
ldi r17, (1<<DDB3)|(1<<DDB2)|(1<<DDB1)|(1<<DDB0)
out PORTB, r16
out DDRB, r17
; Insert nop for synchronization
nop
; Read port pins
in r16, PINB
...
C Code Example
unsigned char i;
...
/* Define pull-ups and set outputs high */
/* Define directions for port pins */
PORTB = (1<<PB7)|(1<<PB6)|(1<<PB1)|(1<<PB0);
DDRB = (1<<DDB3)|(1<<DDB2)|(1<<DDB1)|(1<<DDB0);
/* Insert nop for synchronization*/
_NOP();
/* Read port pins */
i = PINB;
...