atmega32c1 ATMEL Corporation, atmega32c1 Datasheet - Page 174

• Manufacturer Part Number: atmega32c1
• Description: Atmega32m1 Automotive 8-bit Avr Microcontroller With 32k/64k Bytes In-system Programmable Flash
• Manufacturer: ATMEL Corporation

16.4
16.4.1
16.4.2
174
CAN Channel
ATmega32/64/M1/C1
Configuration
Bit Timing
The CAN channel can be in:
Figure 16-6. Listening Mode
FSM’s (Finite State Machine) of the CAN channel need to be synchronous to the time quantum.
So, the input clock for bit timing is the clock used into CAN channel FSM’s.
Field and segment abbreviations:
• Enabled mode
• Standby mode
• Listening mode
• BRP: Baud Rate Prescaler.
• TQ: Time Quantum (output of Baud Rate Prescaler).
• SYNS: SYNchronization Segment is 1 TQ long.
• PRS: PRopagation time Segment is programmable to be 1, 2, ..., 8 TQ long.
• PHS1: PHase Segment 1 is programmable to be 1, 2, ..., 8 TQ long.
• PHS2: PHase Segment 2 is programmable to be ≤ PHS1 and ≥ INFORMATION
• INFORMATION PROCESSING TIME is 2 TQ.
• SJW: (Re) Synchronization Jump Width is programmable between 1 and min(4, PHS1).
PROCESSING TIME.
– the CAN channel (internal TxCAN & RxCAN) is enabled,
– the input clock is enabled.
– the transmitter constantly provides a recessive level (on internal TxCAN) and the
– input clock is enabled,
– the registers and pages remain accessible.
– enables a hardware loop back, internal TxCAN on internal RxCAN
– provides a recessive level on TXCAN output pin
– does not disable RXCAN input pin
– freezes TEC and REC error counters
In this mode:
In standby mode:
This mode is transparent for the CAN channel:
receiver is disabled,
LISTEN
RxCAN
TxCAN
internal
internal
1
0
PD5
PD6
RXCAN
TXCAN
7647A–AVR–02/08