Datasheet

ManualsBrandsMICROCHIP TECHNOLOGY ManualsMicrocontrollers, Microprocessors & QuartzesEmbedded microcontroller QFN 64 (9x9) 8-Bit 16 MHz I/O number 53

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Table Of Contents

Features
1. Description
- 1.1 Comparison Between AT90CAN32, AT90CAN64 and AT90CAN128
- 1.2 Part Description
- 1.3 Disclaimer
- 1.4 Automotive Quality Grade
- 1.5 Block Diagram
- 1.6 Pin Configurations
- 1.7 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
  - 3.5.1 The X-register, Y-register, and Z-register
  - 3.5.2 Extended Z-pointer Register for ELPM/SPM - RAMPZ
- 3.6 Stack Pointer
- 3.7 Instruction Execution Timing
- 3.8 Reset and Interrupt Handling
  - 3.8.1 Interrupt Behavior
  - 3.8.2 Interrupt Response Time
4. Memories
- 4.1 In-System Reprogrammable Flash Program Memory
- 4.2 SRAM Data Memory
  - 4.2.1 SRAM Data Access
  - 4.2.2 SRAM Data Access Times
- 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
  - 5.6.1 Oscillator Calibration Register - OSCCAL
- 5.7 External Clock
- 5.8 Clock Output Buffer
- 5.9 Timer/Counter2 Oscillator
- 5.10 System Clock Prescaler
  - 5.10.1 Clock Prescaler Register - CLKPR
6. Power Management and Sleep Modes
- 6.0.1 Sleep Mode Control Register - SMCR
- 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
  - 7.2.1 Voltage Reference Enable Signals and Start-up Time
  - 7.2.2 Voltage Reference Characteristics
- 7.3 Watchdog Timer
  - 7.3.1 Watchdog Timer Control Register - WDTCR
- 7.4 Timed Sequences for Changing the Configuration of the Watchdog Timer
  - 7.4.1 Safety Level 1
  - 7.4.2 Safety Level 2
8. Interrupts
- 8.1 Interrupt Vectors in AT90CAN32/64/128
- 8.2 Moving Interrupts Between Application and Boot Space
  - 8.2.1 MCU Control Register - MCUCR
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
- 10.0.1 Asynchronous External Interrupt Control Register A - EICRA
- 10.0.2 Synchronous External Interrupt Control Register B - EICRB
- 10.0.3 External Interrupt Mask Register - EIMSK
- 10.0.4 External Interrupt Flag Register - EIFR
11. Timer/Counter3/1/0 Prescalers
- 11.1 Overview
- 11.2 Timer/Counter0/1/3 Prescalers Register Description
  - 11.2.1 General Timer/Counter Control Register - GTCCR
12. 8-bit Timer/Counter0 with PWM
- 12.1 Features
- 12.2 Overview
  - 12.2.1 Registers
  - 12.2.2 Definitions
- 12.3 Timer/Counter Clock Sources
- 12.4 Counter Unit
- 12.5 Output Compare Unit
- 12.6 Compare Match Output Unit
  - 12.6.1 Compare Output Function
  - 12.6.2 Compare Output Mode and Waveform Generation
- 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
  - 13.3.1 Code Examples
  - 13.3.2 Reusing the Temporary High Byte Register
- 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
  - 13.8.1 Compare Output Function
  - 13.8.2 Compare Output Mode and Waveform Generation
- 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
  - 14.2.1 Definitions
- 14.3 Timer/Counter Clock Sources
- 14.4 Counter Unit
- 14.5 Output Compare Unit
- 14.6 Compare Match Output Unit
  - 14.6.1 Compare Output Function
  - 14.6.2 Compare Output Mode and Waveform Generation
- 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
  - 14.11.1 General Timer/Counter Control Register - GTCCR
15. Output Compare Modulator - OCM
- 15.1 Overview
- 15.2 Description
  - 15.2.1 Timing Example
  - 15.2.2 Resolution of the PWM Signal
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
  - 17.5.1 Frame Formats
  - 17.5.2 Parity Bit Calculation
- 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
  - 17.10.1 MPCM Protocol
  - 17.10.2 Using MPCM
- 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
  - 18.2.1 TWI Terminology
  - 18.2.2 Electrical Interconnection
- 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
  - 19.8.1 Interrupt organization
  - 19.8.2 Interrupt Behavior
- 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
  - 20.2.1 ADC Control and Status Register B - ADCSRB
  - 20.2.2 Analog Comparator Control and Status Register - ACSR
- 20.3 Analog Comparator Multiplexed Input
  - 20.3.1 Digital Input Disable Register 1 - DIDR1
21. Analog to Digital Converter - ADC
- 21.1 Features
- 21.2 Operation
- 21.3 Starting a Conversion
- 21.4 Prescaling and Conversion Timing
  - 21.4.1 Differential Channels
- 21.5 Changing Channel or Reference Selection
  - 21.5.1 ADC Input Channels
  - 21.5.2 ADC Voltage Reference
- 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
  - 22.8.1 On-chip Debug Register - OCDR
- 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
  - 23.5.1 MCU Control Register - MCUCR
  - 23.5.2 MCU Status Register - MCUSR
- 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
  - 24.2.1 AS - Application Section
  - 24.2.2 BLS - Boot Loader Section
- 24.3 Read-While-Write and No Read-While-Write Flash Sections
  - 24.3.1 RWW - Read-While-Write Section
  - 24.3.2 NRWW - No Read-While-Write Section
- 24.4 Boot Loader Lock Bits
- 24.5 Entering the Boot Loader Program
  - 24.5.1 Store Program Memory Control and Status Register - SPMCSR
- 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
  - 25.2.1 Latching of Fuses
- 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
  - 25.8.1 Data Polling Flash
  - 25.8.2 Data Polling EEPROM
- 25.9 JTAG Programming Overview
26. Decoupling Capacitors
27. Electrical Characteristics (1)
- 27.1 Absolute Maximum Ratings*
- 27.2 DC Characteristics(1)
- 27.3 External Clock Drive Characteristics
- 27.4 Maximum Speed vs. VCC
- 27.5 Two-wire Serial Interface Characteristics
- 27.6 SPI Timing Characteristics
- 27.7 CAN Physical Layer Characteristics
- 27.8 ADC Characteristics((1)
- 27.9 External Data Memory Characteristics(1)
- 27.10 Parallel Programming Characteristics
28. Register Summary
29. AT90CAN32/64/128 Typical Characteristics
- 29.1 Active Supply Current
- 29.2 Idle Supply Current
- 29.3 Power-down Supply Current
- 29.4 Power-save Supply Current
- 29.5 Pin Pull-up
- 29.6 Pin Driver Strength
- 29.7 Pin Thresholds and Hysteresis
- 29.8 BOD Thresholds and Analog Comparator Offset
- 29.9 Internal Oscillator Speed
- 29.10 Current Consumption of Peripheral Units
- 29.11 Current Consumption in Reset and Reset Pulse Width
- 29.12 Analog To Digital Converter
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 7682A - 01/07
- 34.2 7682B - 09/07
- 34.3 7682C - 04/08

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7682C–AUTO–04/08

AT90CAN32/64/128

priority, the maximum interrupt response time is dependent on the maximum number of clock

cycles it takes to handle any of the other interrupt requests.

Using the Input Capture unit in any mode of operation when the TOP value (resolution) is

actively changed during operation, is not recommended.

Measurement of an external signal’s duty cycle requires that the trigger edge is changed after

each capture. Changing the edge sensing must be done as early as possible after the ICRn

cleared by software (writing a logical one to the I/O bit location). For measuring frequency only,

the clearing of the ICFn flag is not required (if an interrupt handler is used).

13.7 Output Compare Units

The 16-bit comparator continuously compares TCNTn with the Output Compare Register

(OCRnx). If TCNT equals OCRnx the comparator signals a match. A match will set the Output

Compare Flag (OCFnx) at the next timer clock cycle. If enabled (OCIEnx = 1), the Output Com-

pare Flag generates an Output Compare interrupt. The OCFnx flag is automatically cleared

when the interrupt is executed. Alternatively the OCFnx flag can be cleared by software by writ-

ing a logical one to its I/O bit location. The Waveform Generator uses the match signal to

generate an output according to operating mode set by the Waveform Generation mode

(WGMn3:0) bits and Compare Output mode (COMnx1:0) bits. The TOP and BOTTOM signals

are used by the Waveform Generator for handling the special cases of the extreme values in

some modes of operation (See “Modes of Operation” on page 126.)

A special feature of Output Compare unit A allows it to define the Timer/Counter TOP value (i.e.,

counter resolution). In addition to the counter resolution, the TOP value defines the period time

for waveforms generated by the Waveform Generator.

Figure 13-4 shows a block diagram of the Output Compare unit. The elements of the block dia-

gram that are not directly a part of the Output Compare unit are gray shaded.