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3 error setting, 8 interrupts, 1 interrupt organization – Rainbow Electronics ATmega64C1 User Manual

Page 182

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182

7647A–AVR–02/08

ATmega32/64/M1/C1

– end-of-frame

– error delimiter

– overload delimiter

AERR: Acknowledgment error (Tx only). No detection of the dominant bit in the acknowledge

slot.

Figure 16-13. Error Detection Procedures in a Data Frame

16.7.3

Error Setting

The CAN channel can detect some errors on the CAN network.

• In transmission:

The error is set at MOb level.

• In reception:

- The identified has matched:
The error is set at MOb level.
- The identified has not or not yet matched:
The error is set at general level.

After detecting an error, the CAN channel sends an error frame on network. If the CAN channel
detects an error frame on network, it sends its own error frame.

16.8

Interrupts

16.8.1

Interrupt organization

The different interrupts are:

• Interrupt on receive completed OK,

• Interrupt on transmit completed OK,

• Interrupt on error (bit error, stuff error, CRC error, form error, acknowledge error),

• Interrupt on frame buffer full,

• Interrupt on “Bus Off” setting,

• Interrupt on overrun of CAN timer.

The general interrupt enable is provided by ENIT bit and the specific interrupt enable for CAN
timer overrun is provided by ENORVT bit.

Identifier

Message Data

RTR

ACK error

Form error

Stuff error

Bit error

CRC error

Form error

Stuff error

Bit error

ACK

EOF

SOF

CRC

del.

ACK

del.

inter.

Control

CRC

Tx

Rx

Arbitration