Rainbow Electronics AT91CAP9S250A User Manual

Page 718

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6264A–CAP–21-May-07

AT91CAP9S500A/AT91CAP9S250A

This flag is automatically reset when Low power mode is disabled

• WAKEUP: CAN controller is not in Low power Mode

0 = CAN controller is in low power mode.

1 = CAN controller is not in low power mode.

When a WAKEUP event occurs, the CAN controller is synchronized with the bus activity. Messages can be transmitted or
received. The CAN controller clock must be available when a WAKEUP event occurs. This flag is automatically reset when
the CAN Controller enters Low Power mode.

• TOVF: Timer Overflow

0 = The timer has not rolled-over FFFFh to 0000h.

1 = The timer rolls-over FFFFh to 0000h.

This flag is automatically cleared by reading CAN_SR register.

• TSTP Timestamp

0 = No bus activity has been detected.

1 = A start of frame or an end of frame has been detected (according to the TEOF field in the CAN_MR register).

This flag is automatically cleared by reading the CAN_SR register.

• CERR: Mailbox CRC Error

0 = No CRC error occurred during a previous transfer.

1 = A CRC error occurred during a previous transfer.

A CRC error has been detected during last reception.

This flag is automatically cleared by reading CAN_SR register.

• SERR: Mailbox Stuffing Error

0 = No stuffing error occurred during a previous transfer.

1 = A stuffing error occurred during a previous transfer.

A form error results from the detection of more than five consecutive bit with the same polarity.

This flag is automatically cleared by reading CAN_SR register.

• AERR: Acknowledgment Error

0 = No acknowledgment error occurred during a previous transfer.

1 = An acknowledgment error occurred during a previous transfer.

An acknowledgment error is detected when no detection of the dominant bit in the acknowledge slot occurs.

This flag is automatically cleared by reading CAN_SR register.

• FERR: Form Error

0 = No form error occurred during a previous transfer

1 = A form error occurred during a previous transfer

A form error results from violations on one or more of the fixed form of the following bit fields:

– CRC delimiter

– ACK delimiter

– End of frame

– Error delimiter

– Overload delimiter

This flag is automatically cleared by reading CAN_SR register.

• BERR: Bit Error

0 = No bit error occurred during a previous transfer.

1 = A bit error occurred during a previous transfer.

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