STMicroelectronics STM32F405 Reference Manual page 1100

Controller area network (bxCAN)
CAN mailbox data length control and time stamp register (CAN_TDTxR)
(x=0..2)
All bits of this register are write protected when the mailbox is not in empty state.
Address offsets: 0x184, 0x194, 0x1A4
Reset value: 0xXXXX XXXX
31 30 29
rw rw rw
15 14 13
Reserved
Bits 31:16 TIME[15:0]
Bits 15:9 Reserved, must be kept at reset value.
Bit 8 TGT
Bits 7:4 Reserved, must be kept at reset value.
Bits 3:0 DLC[3:0]
1100/1731
28 27 26 25
rw rw rw rw
12 11 10 9
:
Message time stamp
This field contains the 16-bit timer value captured at the SOF transmission.
:
Transmit global time
This bit is active only when the hardware is in the Time Trigger Communication mode,
TTCM bit of the CAN_MCR register is set.
0: Time stamp TIME[15:0] is not sent.
1: Time stamp TIME[15:0] value is sent in the last two data bytes of the 8-byte message:
TIME[7:0] in data byte 7 and TIME[15:8] in data byte 6, replacing the data written in
CAN_TDHxR[31:16] register (DATA6[7:0] and DATA7[7:0]). DLC must be programmed as 8
in order these two bytes to be sent over the CAN bus.
:
Data length code
This field defines the number of data bytes a data frame contains or a remote frame request.
A message can contain from 0 to 8 data bytes, depending on the value in the DLC field.
DocID018909 Rev 11
24 23 22 21
TIME[15:0]
rw rw rw rw
8 7 6 5
TGT
Reserved
rw
20 19 18 17
rw rw rw rw
4 3 2 1
DLC[3:0]
rw rw rw
RM0090
16
rw
0
rw