Datasheet
Table Of Contents
- 1. Description
- 2. About Code Examples
- 3. AVR CPU Core
- 4. Memories
- 5. System Clock
- 6. Power Management and Sleep Modes
- 7. System Control and Reset
- 8. Interrupts
- 9. I/O-Ports
- 10. External Interrupts
- 11. Timer/Counter3/1/0 Prescalers
- 12. 8-bit Timer/Counter0 with PWM
- 13. 16-bit Timer/Counter (Timer/Counter1 and Timer/Counter3)
- 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
- 16. Serial Peripheral Interface - SPI
- 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
- 19. Controller Area Network - CAN
- 20. Analog Comparator
- 21. Analog to Digital Converter - ADC
- 22. JTAG Interface and On-chip Debug System
- 23. Boundary-scan IEEE 1149.1 (JTAG)
- 24. Boot Loader Support - Read-While-Write Self-Programming
- 25. Memory Programming
- 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
- 33. Errata
- 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

259
7679H–CAN–08/08
AT90CAN32/64/128
• Bit 7– Reserved Bit
This bit is reserved for future use. For compatibility with future devices, it must be written to zero
when CANBT3 is written.
• Bit 6:4 – PHS22:0: Phase Segment 2
This phase is used to compensate for phase edge errors. This segment may be shortened by
the re-synchronization jump width. PHS2[2..0] shall be ≥1 and ≤PHS1[2..0] (c.f. Section 19.2.3
”CAN Bit Timing” on page 236 and Section 19.4.3 ”Baud Rate” on page 242).
• Bit 3:1 – PHS12:0: Phase Segment 1
This phase is used to compensate for phase edge errors. This segment may be lengthened by
the re-synchronization jump width.
• Bit 0 – SMP: Sample Point(s)
This option allows to filter possible noise on TxCAN input pin.
– 0 - the sampling will occur once at the user configured sampling point - SP.
– 1 - with three-point sampling configuration the first sampling will occur two
Tclk
IO
clocks before the user configured sampling point - SP, again at one
Tclk
IO
clock
before SP and finally at SP. Then the bit level will be determined by a majority vote of
the three samples.
‘SMP=1’ configuration is not compatible with ‘BRP[5:0]=0’ because TQ =
Tclk
IO
.
If BRP = 0, SMP must be cleared.
19.10.11 CAN Timer Control Register - CANTCON
• Bit 7:0 – TPRSC7:0: CAN Timer Prescaler
Prescaler for the CAN timer upper counter range 0 to 255. It provides the clock to the CAN timer
if the CAN controller is enabled.
Tclk
CANTIM
= Tclk
IO
x 8 x (CANTCON [7:0] + 1)
19.10.12 CAN Timer Registers - CANTIML and CANTIMH
• Bits 15:0 - CANTIM15:0: CAN Timer Count
CAN timer counter range 0 to 65,535.
Tphs2 = Tscl x (PHS2 [2:0] + 1)
Tphs1 = Tscl x (PHS1 [2:0] + 1)
Bit 76543210
TPRSC7 TPRSC6 TPRSC5 TPRSC4 TPRSC3 TPRSC2 TRPSC1 TPRSC0 CANTCON
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value00000000
Bit76543210
CANTIM7 CANTIM6 CANTIM5 CANTIM4 CANTIM3 CANTIM2 CANTIM1 CANTIM0 CANTIML
CANTIM15 CANTIM14 CANTIM13 CANTIM12 CANTIM11 CANTIM10 CANTIM9 CANTIM8 CANTIMH
Bit 1514131211109 8
Read/WriteRRRRRRRR
Initial Value00000000