MCAN_CCCR

MCAN CC Control Register

  0x18 32 Read/Write 0x00000001  

MCAN CC Control Register

Bit  31 30 29 28 27 26 25 24  
                   
Access                   
Reset                   
Bit  23 22 21 20 19 18 17 16  
                   
Access                   
Reset                   
Bit  15 14 13 12 11 10 9 8  
  NISO TXP EFBI PXHD     BRSE FDOE  
Access  R/W R/W R/W R/W     R/W R/W  
Reset  0 0 0 0     0 0  
Bit  7 6 5 4 3 2 1 0  
  TEST DAR MON CSR CSA ASM CCE INIT  
Access  R/W R/W R/W R/W R R/W R/W R/W  
Reset  0 0 0 0 0 0 0 1  

Bit 0 – INIT: Initialization (read/write)

Initialization (read/write)

Due to the synchronization mechanism between the two clock domains, there may be a delay until the value written to INIT can be read back. Therefore the programmer has to ensure that the previous value written to INIT has been accepted by reading INIT before setting INIT to a new value.

0 (DISABLED): Normal operation.

1 (ENABLED): Initialization is started.

Bit 1 – CCE: Configuration Change Enable (read/write, write protection)

Configuration Change Enable (read/write, write protection)

0 (PROTECTED): The processor has no write access to the protected configuration registers.

1 (CONFIGURABLE): The processor has write access to the protected configuration registers (while MCAN_CCCR.INIT = ‘1’).

Bit 2 – ASM: Restricted Operation Mode (read/write, write protection against ‘1’)

Restricted Operation Mode (read/write, write protection against ‘1’)

For a description of the Restricted Operation mode see Restricted Operation Mode.

0 (NORMAL): Normal CAN operation.

1 (RESTRICTED): Restricted Operation mode active.

Bit 3 – CSA: Clock Stop Acknowledge (read-only)

Clock Stop Acknowledge (read-only)

ValueDescription
0

No clock stop acknowledged.

1

MCAN may be set in power down by stopping the peripheral clock and the CAN core clock.

Bit 4 – CSR: Clock Stop Request (read/write)

Clock Stop Request (read/write)

0 (NO_CLOCK_STOP): No clock stop is requested.

1 (CLOCK_STOP): Clock stop requested. When clock stop is requested, first INIT and then CSA will be set after all pending transfer requests have been completed and the CAN bus reached idle.

Bit 5 – MON: Bus Monitoring Mode (read/write, write protection against ‘1’)

Bus Monitoring Mode (read/write, write protection against ‘1’)

0 (DISABLED): Bus Monitoring mode is disabled.

1 (ENABLED): Bus Monitoring mode is enabled.

Bit 6 – DAR: Disable Automatic Retransmission (read/write, write protection)

Disable Automatic Retransmission (read/write, write protection)

0 (AUTO_RETX): Automatic retransmission of messages not transmitted successfully enabled.

1 (NO_AUTO_RETX): Automatic retransmission disabled.

Bit 7 – TEST: Test Mode Enable (read/write, write protection against ‘1’)

Test Mode Enable (read/write, write protection against ‘1’)

0 (DISABLED): Normal operation, MCAN_TEST register holds reset values.

1 (ENABLED): Test mode, write access to MCAN_TEST register enabled.

Bit 8 – FDOE: CAN FD Operation Enable (read/write, write protection)

CAN FD Operation Enable (read/write, write protection)

0 (DISABLED): FD operation disabled.

1 (ENABLED): FD operation enabled.

Bit 9 – BRSE: Bit Rate Switching Enable (read/write, write protection)

Bit Rate Switching Enable (read/write, write protection)

0 (DISABLED): Bit rate switching for transmissions disabled.

1 (ENABLED): Bit rate switching for transmissions enabled.

Bit 12 – PXHD: Protocol Exception Event Handling (read/write, write protection)

Protocol Exception Event Handling (read/write, write protection)

ValueDescription
0

Protocol exception handling enabled.

1

Protocol exception handling disabled.

Bit 13 – EFBI: Edge Filtering during Bus Integration (read/write, write protection)

Edge Filtering during Bus Integration (read/write, write protection)

ValueDescription
0

Edge filtering is disabled.

1

Edge filtering is enabled. Two consecutive dominant tq required to detect an edge for hard synchronization.

Bit 14 – TXP: Transmit Pause (read/write, write protection)

Transmit Pause (read/write, write protection)

If this bit is set, the MCAN pauses for two CAN bit times before starting the next transmission after itself has successfully transmitted a frame (see Tx Handling).

ValueDescription
0

Transmit pause disabled.

1

Transmit pause enabled.

Bit 15 – NISO: Non-ISO Operation

Non-ISO Operation

If this bit is set, the MCAN uses the CAN FD frame format as specified by the Bosch CAN FD Specification V1.0.

ValueDescription
0

CAN FD frame format according to ISO11898-1 (default).

1

CAN FD frame format according to Bosch CAN FD Specification V1.0.