Datasheet

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Table Of Contents

1. Description
- 1.1 Comparison Between AT90CAN32, AT90CAN64 and AT90CAN128
- 1.2 Part Description
- 1.3 Disclaimer
- 1.4 Block Diagram
- 1.5 Pin Configurations
- 1.6 Pin Descriptions
2. About Code Examples
3. AVR CPU Core
- 3.1 Introduction
- 3.2 Architectural Overview
- 3.3 ALU - Arithmetic Logic Unit
- 3.4 Status Register
- 3.5 General Purpose Register File
- 3.6 Stack Pointer
- 3.7 Instruction Execution Timing
- 3.8 Reset and Interrupt Handling
4. Memories
- 4.1 In-System Reprogrammable Flash Program Memory
- 4.2 SRAM Data Memory
- 4.3 EEPROM Data Memory
- 4.4 I/O Memory
- 4.5 External Memory Interface
- 4.6 General Purpose I/O Registers
5. System Clock
- 5.1 Clock Systems and their Distribution
- 5.2 Clock Sources
- 5.3 Default Clock Source
- 5.4 Crystal Oscillator
- 5.5 Low-frequency Crystal Oscillator
- 5.6 Calibrated Internal RC Oscillator
- 5.7 External Clock
- 5.8 Clock Output Buffer
- 5.9 Timer/Counter2 Oscillator
- 5.10 System Clock Prescaler
6. Power Management and Sleep Modes
- 6.1 Idle Mode
- 6.2 ADC Noise Reduction Mode
- 6.3 Power-down Mode
- 6.4 Power-save Mode
- 6.5 Standby Mode
- 6.6 Minimizing Power Consumption
7. System Control and Reset
- 7.1 Reset
- 7.2 Internal Voltage Reference
- 7.3 Watchdog Timer
- 7.4 Timed Sequences for Changing the Configuration of the Watchdog Timer
8. Interrupts
- 8.1 Interrupt Vectors in AT90CAN32/64/128
- 8.2 Moving Interrupts Between Application and Boot Space
9. I/O-Ports
- 9.1 Introduction
- 9.2 Ports as General Digital I/O
- 9.3 Alternate Port Functions
- 9.4 Register Description for I/O-Ports
10. External Interrupts
- 10.1 External Interrupt Register Description
11. Timer/Counter3/1/0 Prescalers
- 11.1 Overview
- 11.2 Timer/Counter0/1/3 Prescalers Register Description
12. 8-bit Timer/Counter0 with PWM
- 12.1 Features
- 12.2 Overview
- 12.3 Timer/Counter Clock Sources
- 12.4 Counter Unit
- 12.5 Output Compare Unit
- 12.6 Compare Match Output Unit
- 12.7 Modes of Operation
- 12.8 Timer/Counter Timing Diagrams
- 12.9 8-bit Timer/Counter Register Description
13. 16-bit Timer/Counter (Timer/Counter1 and Timer/Counter3)
- 13.1 Features
- 13.2 Overview
- 13.3 Accessing 16-bit Registers
- 13.4 Timer/Counter Clock Sources
- 13.5 Counter Unit
- 13.6 Input Capture Unit
- 13.7 Output Compare Units
- 13.8 Compare Match Output Unit
- 13.9 Modes of Operation
- 13.10 Timer/Counter Timing Diagrams
- 13.11 16-bit Timer/Counter Register Description
14. 8-bit Timer/Counter2 with PWM and Asynchronous Operation
- 14.1 Features
- 14.2 Overview
- 14.3 Timer/Counter Clock Sources
- 14.4 Counter Unit
- 14.5 Output Compare Unit
- 14.6 Compare Match Output Unit
- 14.7 Modes of Operation
- 14.8 Timer/Counter Timing Diagrams
- 14.9 8-bit Timer/Counter Register Description
- 14.10 Asynchronous operation of the Timer/Counter2
- 14.11 Timer/Counter2 Prescaler
15. Output Compare Modulator - OCM
- 15.1 Overview
- 15.2 Description
16. Serial Peripheral Interface - SPI
- 16.1 Features
- 16.2 SS Pin Functionality
- 16.3 Data Modes
17. USART (USART0 and USART1)
- 17.1 Features
- 17.2 Overview
- 17.3 Dual USART
- 17.4 Clock Generation
- 17.5 Serial Frame
- 17.6 USART Initialization
- 17.7 Data Transmission - USART Transmitter
- 17.8 Data Reception - USART Receiver
- 17.9 Asynchronous Data Reception
- 17.10 Multi-processor Communication Mode
- 17.11 USART Register Description
- 17.12 Examples of Baud Rate Setting
18. Two-wire Serial Interface
- 18.1 Features
- 18.2 Two-wire Serial Interface Bus Definition
- 18.3 Data Transfer and Frame Format
- 18.4 Multi-master Bus Systems, Arbitration and Synchronization
- 18.5 Overview of the TWI Module
- 18.6 TWI Register Description
- 18.7 Using the TWI
- 18.8 Transmission Modes
- 18.9 Multi-master Systems and Arbitration
19. Controller Area Network - CAN
- 19.1 Features
- 19.2 CAN Protocol
- 19.3 CAN Controller
- 19.4 CAN Channel
- 19.5 Message Objects
- 19.6 CAN Timer
- 19.7 Error Management
- 19.8 Interrupts
- 19.9 CAN Register Description
- 19.10 General CAN Registers
- 19.11 MOb Registers
- 19.12 Examples of CAN Baud Rate Setting
20. Analog Comparator
- 20.1 Overview
- 20.2 Analog Comparator Register Description
- 20.3 Analog Comparator Multiplexed Input
21. Analog to Digital Converter - ADC
- 21.1 Features
- 21.2 Operation
- 21.3 Starting a Conversion
- 21.4 Prescaling and Conversion Timing
- 21.5 Changing Channel or Reference Selection
- 21.6 ADC Noise Canceler
- 21.7 ADC Conversion Result
- 21.8 ADC Register Description
22. JTAG Interface and On-chip Debug System
- 22.1 Features
- 22.2 Overview
- 22.3 Test Access Port - TAP
- 22.4 TAP Controller
- 22.5 Using the Boundary-scan Chain
- 22.6 Using the On-chip Debug System
- 22.7 On-chip Debug Specific JTAG Instructions
- 22.8 On-chip Debug Related Register in I/O Memory
- 22.9 Using the JTAG Programming Capabilities
- 22.10 Bibliography
23. Boundary-scan IEEE 1149.1 (JTAG)
- 23.1 Features
- 23.2 System Overview
- 23.3 Data Registers
- 23.4 Boundary-scan Specific JTAG Instructions
- 23.5 Boundary-scan Related Register in I/O Memory
- 23.6 Boundary-scan Chain
- 23.7 AT90CAN32/64/128 Boundary-scan Order
- 23.8 Boundary-scan Description Language Files
24. Boot Loader Support - Read-While-Write Self-Programming
- 24.1 Features
- 24.2 Application and Boot Loader Flash Sections
- 24.3 Read-While-Write and No Read-While-Write Flash Sections
- 24.4 Boot Loader Lock Bits
- 24.5 Entering the Boot Loader Program
- 24.6 Addressing the Flash During Self-Programming
- 24.7 Self-Programming the Flash
25. Memory Programming
- 25.1 Program and Data Memory Lock Bits
- 25.2 Fuse Bits
- 25.3 Signature Bytes
- 25.4 Calibration Byte
- 25.5 Parallel Programming Overview
- 25.6 Parallel Programming
- 25.7 SPI Serial Programming Overview
- 25.8 SPI Serial Programming
- 25.9 JTAG Programming Overview
26. Electrical Characteristics (1)
- 26.1 Absolute Maximum Ratings*
- 26.2 DC Characteristics
- 26.3 External Clock Drive Characteristics
- 26.4 Maximum Speed vs. VCC
- 26.5 Two-wire Serial Interface Characteristics
- 26.6 SPI Timing Characteristics
- 26.7 CAN Physical Layer Characteristics
- 26.8 ADC Characteristics
- 26.9 External Data Memory Characteristics
- 26.10 Parallel Programming Characteristics
27. Decoupling Capacitors
28. AT90CAN32/64/128 Typical Characteristics
- 28.1 Active Supply Current
- 28.2 Idle Supply Current
- 28.3 Power-down Supply Current
- 28.4 Power-save Supply Current
- 28.5 Standby Supply Current
- 28.6 Pin Pull-up
- 28.7 Pin Driver Strength
- 28.8 Pin Thresholds and Hysteresis
- 28.9 BOD Thresholds and Analog Comparator Offset
- 28.10 Internal Oscillator Speed
- 28.11 Current Consumption of Peripheral Units
- 28.12 Current Consumption in Reset and Reset Pulse Width
29. Register Summary
30. Instruction Set Summary
31. Ordering Information
32. Packaging Information
- 32.1 TQFP64
- 32.2 QFN64
33. Errata
- 33.1 Errata Summary
- 33.2 Errata Description
34. Datasheet Revision History for AT90CAN32/64/128
- 34.1 Changes from 7679G - 03/08 to 7679H - 08/08
- 34.2 Changes from 7679F - 11/07 to 7679G - 03/08
- 34.3 Changes from 7679E - 07/07 to 7679F - 11/07
- 34.4 Changes from 7679D - 02/07 to 7679E - 07/07
- 34.5 Changes from 7679C - 01/07 to 7679D - 02/07
- 34.6 Changes from 7679B - 11/06 to 7679C - 01/07
- 34.7 Changes from 7679A - 10/06 to 7679B - 11/06
- 34.8 Document Creation

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7679H–CAN–08/08

AT90CAN32/64/128

– 0 - standby mode: The on-going transmission (if exists) is normally terminated and the

CAN channel is frozen (the CONMOB bits of every MOb do not change). The transmitter

constantly provides a recessive level. In this mode, the receiver is not enabled but all the

registers and mailbox remain accessible from CPU.

Note: A standby mode applied during a reception may corrupt the on-going reception or set the

controller in a wrong state. The controller will restart correctly from this state if a software

reset (SWRES) is applied. If no reset is considered, a possible solution is to wait for a

lake of a receiver busy (RXBSY) before to enter in stand-by mode. The best solution is

first to apply an abort request command (ABRQ) and then wait for the lake of the receiver

busy (RXBSY) before to enter in stand-by mode. In any cases, this standby mode behav-

ior has no effect on the CAN bus integrity.

– 1 - enable mode: The CAN channel enters in enable mode once 11 recessive bits

has been read.

• Bit 0 – SWRES: Software Reset Request

This auto resettable bit only resets the CAN controller.

–0 - no reset

– 1 - reset: this reset is “ORed” with the hardware reset.

19.10.2 CAN General Status Register - CANGSTA

• Bit 7 – Reserved Bit

This bit is reserved for future use.

• Bit 6 – OVRG: Overload Frame Flag

This flag does not generate an interrupt.

– 0 - no overload frame.

– 1 - overload frame: set by hardware as long as the produced overload frame is sent.

• Bit 5 – Reserved Bit

This bit is reserved for future use.

• Bit 4 – TXBSY: Transmitter Busy

This flag does not generate an interrupt.

– 0 - transmitter not busy.

– 1 - transmitter busy: set by hardware as long as a frame (data, remote, overload or

error frame) or an ACK field is sent. Also set when an inter frame space is sent.

• Bit 3 – RXBSY: Receiver Busy

This flag does not generate an interrupt.

– 0 - receiver not busy

– 1 - receiver busy: set by hardware as long as a frame is received or monitored.

• Bit 2 – ENFG: Enable Flag

Bit 76543210

- OVRG - TXBSY RXBSY ENFG BOFF ERRP CANGSTA

Read/Write - R - R R R R R

Initial Value-0-00000