ST STM32F102 Series Reference Manual page 532

Controller area network (bxCAN)
Bit 2 IDE: Identifier Extension
This bit defines the identifier type of message in the mailbox.
0: Standard identifier.
1: Extended identifier.
Bit 1 RTR: Remote Transmission Request
0: Data frame
1: Remote frame
Bit 0 Reserved
Receive FIFO mailbox data length control and time stamp register
(CAN_RDTxR) (x=0..1)
Address offsets: 0x1B4, 0x1C4
Reset value: 0xXX where X is undefined
Note: All RX registers are write protected.
31 30 29
r r r
15 14 13
r r r
Bits 31:16 TIME[15:0]: Message Time Stamp
This field contains the 16-bit timer value captured at the SOF detection.
Bits 15:8 FMI[7:0]: Filter Match Index
This register contains the index of the filter the message stored in the mailbox passed through. For
more details on identifier filtering please refer to
Filter Match Index paragraph.
Bits 7:4 Reserved, forced by hardware to 0.
Bits 3:0 DLC[3:0]: Data Length Code
This field defines the number of data bytes a data frame contains (0 to 8). It is 0 in the case of a
remote frame request.
532/690
28 27 26 25
r r r r
12 11 10 9
FMI[7:0]
r r r r
24 23 22 21
TIME[15:0]
r r r r
8 7 6 5
Reserved
r Res.
Section 21.4.4: Identifier filtering on page 508
20 19 18 17
r r r r
4 3 2 1
DLC[3:0]
r r r
RM0008
16
r
0
r
-