MCAN Protocol Status Register
Bit | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | |
Access | |||||||||
Reset |
Bit | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | |
TDCV[6:0] | |||||||||
Access | R | R | R | R | R | R | R | ||
Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Bit | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | |
PXE | RFDF | RBRS | RESI | DLEC[2:0] | |||||
Access | |||||||||
Reset | 0 | 0 | 0 | 0 | 1 | 1 | 1 |
Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
BO | EW | EP | ACT[1:0] | LEC[2:0] | |||||
Access | R | R | R | R | R | ||||
Reset | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 |
Last Error Code (set to 111 on read)
The LEC indicates the type of the last error to occur on the CAN bus. This field is cleared when a message has been transferred (reception or transmission) without error.
Value | Name | Description |
---|---|---|
0 | NO_ERROR | No error occurred since LEC has been reset by successful reception or transmission. |
1 | STUFF_ERROR | More than 5 equal bits in a sequence have occurred in a part of a received message where this is not allowed. |
2 | FORM_ERROR | A fixed format part of a received frame has the wrong format. |
3 | ACK_ERROR | The message transmitted by the MCAN was not acknowledged by another node. |
4 | BIT1_ERROR | During transmission of a message (with the exception of the arbitration field), the device tried to send a recessive level (bit of logical value ‘1’), but the monitored bus value was dominant. |
5 | BIT0_ERROR | During transmission of a message (or acknowledge bit, or active error flag, or overload flag), the device tried to send a dominant level (data or identifier bit logical value ‘0’), but the monitored bus value was recessive. During Bus_Off recovery, this status is set each time a sequence of 11 recessive bits has been monitored. This enables the processor to monitor the proceeding of the Bus_Off recovery sequence (indicating the bus is not stuck at dominant or continuously disturbed). |
6 | CRC_ERROR | The CRC check sum of a received message was incorrect. The CRC of an incoming message does not match the CRC calculated from the received data. |
7 | NO_CHANGE | Any read access to the Protocol Status Register re-initializes the LEC to ‘7’. When the LEC shows value ‘7’, no CAN bus event was detected since the last processor read access to the Protocol Status Register. |
Activity
Monitors the CAN communication state of the CAN module.
Value | Name | Description |
---|---|---|
0 | SYNCHRONIZING | Node is synchronizing on CAN communication |
1 | IDLE | Node is neither receiver nor transmitter |
2 | RECEIVER | Node is operating as receiver |
3 | TRANSMITTER | Node is operating as transmitter |
Error Passive
Value | Description |
---|---|
0 | The MCAN is in the Error_Active state. It normally takes part in bus communication and sends an active error flag when an error has been detected. |
1 | The MCAN is in the Error_Passive state. |
Warning Status
Value | Description |
---|---|
0 | Both error counters are below the Error_Warning limit of 96. |
1 | At least one of error counter has reached the Error_Warning limit of 96. |
Bus_Off Status
Value | Description |
---|---|
0 | The MCAN is not Bus_Off. |
1 | The MCAN is in Bus_Off state. |
Data Phase Last Error Code (set to 111 on read)
Type of last error that occurred in the data phase of a CAN FD format frame with its BRS flag set. Coding is the same as for LEC. This field will be cleared to zero when a CAN FD format frame with its BRS flag set has been transferred (reception or transmission) without error.
ESI Flag of Last Received CAN FD Message (cleared on read)
This bit is set together with RFDF, independently from acceptance filtering.
Value | Description |
---|---|
0 | Last received CAN FD message did not have its ESI flag set. |
1 | Last received CAN FD message had its ESI flag set. |
BRS Flag of Last Received CAN FD Message (cleared on read)
This bit is set together with RFDF, independently from acceptance filtering.
Value | Description |
---|---|
0 | Last received CAN FD message did not have its BRS flag set. |
1 | Last received CAN FD message had its BRS flag set. |
Received a CAN FD Message (cleared on read)
This bit is set independently from acceptance filtering.
Value | Description |
---|---|
0 | Since this bit was reset by the CPU, no CAN FD message has been received |
1 | Message in CAN FD format with FDF flag set has been received |
Protocol Exception Event (cleared on read)
Value | Description |
---|---|
0 | No protocol exception event occurred since last read access |
1 | Protocol exception event occurred |
Transmitter Delay Compensation Value
0 to 127: Position of the secondary sample point, in CAN core clock periods, defined by the sum of the measured delay from CANTX to CANRX and MCAN_TDCR.TDCO.