38.13.1 CxCON
Note:
- The individual bytes in this
multibyte register can be accessed with the following register names:
- CxCONT: Accesses the top byte CON[31:24]
- CxCONU: Accesses the upper byte CON[23:16]
- CxCONH: Accesses the high byte CON[15:8]
- CxCONL: Accesses the low byte CON[7:0]
- These bits can only be
modified in Configuration mode (OPMOD[2:0] =
100
).
Name: | CxCON |
Offset: | 0x0100 |
Bit | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | |
TXBWS[3:0] | ABAT | REQOP[2:0] | |||||||
Access | R/W | R/W | R/W | R/W | S/HC | R/W | R/W | R/W | |
Reset | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 |
Bit | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | |
OPMOD[2:0] | TXQEN | STEF | SERRLOM | ESIGM | RTXAT | ||||
Access | R | R | R | R/W | R/W | R/W | R/W | R/W | |
Reset | 1 | 0 | 0 | 1 | 1 | 0 | 0 | 0 |
Bit | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | |
ON | SIDL | BRSDIS | BUSY | WFT[1:0] | WAKFIL | ||||
Access | R/W | R/W | R/W | R | R/W | R/W | R/W | ||
Reset | 0 | 0 | 0 | 0 | 1 | 1 | 1 |
Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
CLKSEL | PXEDIS | ISOCRCEN | DNCNT[4:0] | ||||||
Access | R/W | R/W | R/W | R/W | R/W | R/W | R/W | R/W | |
Reset | 0 | 1 | 1 | 0 | 0 | 0 | 0 | 0 |
Bits 31:28 – TXBWS[3:0] Transmit Bandwidth Sharing
Value | Description |
---|---|
1111-1100 | 4096 |
1011 | 2048 |
1010 | 1024 |
1001 | 512 |
1000 | 256 |
0111 | 128 |
0110 | 64 |
0101 | 32 |
0100 | 16 |
0011 | 8 |
0010 | 4 |
0001 | 2 |
0000 | No delay |
Bit 27 – ABAT Abort All Pending Transmissions
Value | Description |
---|---|
1 | Signals all transmit buffers to abort transmission |
0 | Module will clear this bit when all transmissions are aborted |
Bits 26:24 – REQOP[2:0] Request Operation Mode
Value | Description |
---|---|
111 | Sets Restricted Operation mode |
110 | Sets Normal CAN 2.0 mode; error frames on CAN FD frames |
101 | Sets External Loopback mode |
100 | Sets Configuration mode |
011 | Sets Listen Only mode |
010 | Sets Internal Loopback mode |
001 | Sets Disable mode |
000 | Sets Normal CAN FD mode; supports mixing of full CAN FD and Classic CAN 2.0 frames |
Bits 23:21 – OPMOD[2:0] Operation Mode Status
Value | Description |
---|---|
111 | Module is in Restricted Operation mode |
110 | Module is in Normal CAN 2.0 mode; error frames on CAN FD frames |
101 | Module is in External Loopback mode |
100 | Module is in Configuration mode |
011 | Module is in Listen Only mode |
010 | Module is in Internal Loopback mode |
001 | Module is in Disable mode |
000 | Module is in Normal CAN FD mode; supports mixing of full CAN FD and Classic CAN 2.0 frames |
Bit 20 – TXQEN Enable Transmit Queue(2)
Value | Description |
---|---|
1 | Enables TXQ and reserves space in RAM |
0 | Does not reserve space in RAM for TXQ |
Bit 19 – STEF Store in Transmit Event FIFO(2)
Value | Description |
---|---|
1 | Saves transmitted messages in TEF |
0 | Does not save transmitted messages in TEF |
Bit 18 – SERRLOM Transition to Listen Only Mode on System Error(2)
Value | Description |
---|---|
1 | Transitions to Listen Only mode on System Error |
0 | Transitions to Restricted Operation mode on System Error |
Bit 17 – ESIGM Transmit ESI in Gateway Mode(2)
Value | Description |
---|---|
1 | ESI is transmitted as recessive when the ESI of message is high or CAN controller is error passive |
0 | ESI reflects error status of the CAN controller |
Bit 16 – RTXAT Restrict Retransmission Attempts(2)
Value | Description |
---|---|
1 | Restricted retransmissions attempts, uses TXAT[1:0] |
0 | Unlimited number of retransmission attempts, TXAT[1:0] bits will be ignored |
Bit 15 – ON CAN Enable
Value | Description |
---|---|
1 | CAN module is enabled |
0 | CAN module is disabled |
Bit 13 – SIDL CAN stop in Idle mode
Value | Description |
---|---|
1 | Stops module operation in Idle mode |
0 | Does not stop module operation in Idle mode |
Bit 12 – BRSDIS Bit Rate Switching (BRS) Disable
Value | Description |
---|---|
1 | Bit rate switching is disabled, regardless of BRS in the transmit message object |
0 | Bit rate switching depends on the BRS of the transmit message object |
Bit 11 – BUSY CAN Module is Busy
Value | Description |
---|---|
1 | The CAN module is active |
0 | The CAN module is inactive |
Bits 10:9 – WFT[1:0] Selectable Wake-up Filter Time
Value | Description |
---|---|
11 | T11 Filter |
10 | T10 Filter |
01 | T01 Filter |
00 | T00 Filter |
Bit 8 – WAKFIL Enable CAN Bus Line Wake-up Filter(2)
Value | Description |
---|---|
1 | Uses CAN bus line filter for wake-up |
0 | CAN bus line filter is not used for wake-up |
Bit 7 – CLKSEL CAN Module Clock Source Select(2)
Value | Description |
---|---|
1 | CAN module is run from EXTCLK |
0 | CAN module is run from system clock |
Bit 6 – PXEDIS Protocol Exception Event Detection Disabled(2)
Value | Description |
---|---|
1 | Protocol exception is treated as a form error |
0 | If a protocol exception is detected, CAN will enter the Bus Integrating state |
Bit 5 – ISOCRCEN Enable ISO CRC in CAN FD Frames(2)
Value | Description |
---|---|
1 | Includes stuff bit count in CRC field and uses nonzero CRC initialization vector |
0 | Does not include stuff bit count in CRC field and uses CRC initialization vector with all zeroes |
Bits 4:0 – DNCNT[4:0] DeviceNet™ Filter Bit Number (see Filtering on Data Bytes and Table 38-9 for more details
Value | Description |
---|---|
11111-10011 | Invalid selection (compares up to 18 bits of data with EIDx) |
10010 | Compares up to Data Byte 2, bit 6 with EID17 |
10001 | Compares up to Data byte 2, bit 7 with EID16 |
... | ... |
00010 | Compares up to Data byte 0 bit 6 with EID1 |
00001 | Compares up to Data byte 0 bit 7 with EID0 |
00000 | Does not compare data bytes |