ST STM32F40 Series Reference Manual page 689

Controller area network (bxCAN)
Bit 8 RQCP1
Set by hardware when the last request (transmit or abort) has been performed.
Cleared by software writing a "1" or by hardware on transmission request (TXRQ1 set in
CAN_TI1R register).
Clearing this bit clears all the status bits (TXOK1, ALST1 and TERR1) for Mailbox 1.
Bit 7 ABRQ0
Set by software to abort the transmission request for the corresponding mailbox.
Cleared by hardware when the mailbox becomes empty.
Setting this bit has no effect when the mailbox is not pending for transmission.
Bits 6:4 Reserved, must be kept at reset value.
Bit 3 TERR0
This bit is set when the previous TX failed due to an error.
Bit 2 ALST0
This bit is set when the previous TX failed due to an arbitration lost.
Bit 1 TXOK0
The hardware updates this bit after each transmission attempt.
0: The previous transmission failed
1: The previous transmission was successful
This bit is set by hardware when the transmission request on mailbox 1 has been completed
successfully. Please refer to
Bit 0 RQCP0
Set by hardware when the last request (transmit or abort) has been performed.
Cleared by software writing a "1" or by hardware on transmission request (TXRQ0 set in
CAN_TI0R register).
Clearing this bit clears all the status bits (TXOK0, ALST0 and TERR0) for Mailbox 0.
CAN receive FIFO 0 register (CAN_RF0R)
Address offset: 0x0C
Reset value: 0x0000 0000
31 30 29
15 14 13
Bit 31:6 Reserved, must be kept at reset value.
Bit 5 RFOM0
Set by software to release the output mailbox of the FIFO. The output mailbox can only be
released when at least one message is pending in the FIFO. Setting this bit when the FIFO
is empty has no effect. If at least two messages are pending in the FIFO, the software has to
release the output mailbox to access the next message.
Cleared by hardware when the output mailbox has been released.
689/1422
:
Request completed mailbox1
:
Abort request for mailbox0
:
Transmission error of mailbox0
:
Arbitration lost for mailbox0
:
Transmission OK of mailbox0
:
Request completed mailbox0
28 27 26 25
12 11 10 9
Reserved
:
Release FIFO 0 output mailbox
Doc ID 018909 Rev 4
Figure 229
24 23 22 21
Reserved
8 7 6 5
RFOM0 FOVR0 FULL0
rs
20 19 18 17
4 3 2 1
Res.
rc_w1 rc_w1
RM0090
16
0
FMP0[1:0]
r r