Table 559. Tx Buffer Request Pending Register Field Descriptions - STMicroelectronics SPC572L series Reference Manual

CAN Subsystem
44.3.5.2.34 Tx Buffer Request Pending Register (TXBRP)
Address: 0x00CC
0 1
R
W
Reset 0 0
16 17 18
R
W
Reset 0 0

Table 559. Tx Buffer Request Pending register field descriptions

Field
Transmission Request Pending
Each Tx Buffer has its own Transmission Request Pending bit. The bits are set via register
TXBAR. The bits are reset after a requested transmission has completed or has been cancelled via
register TXBCR.
TXBRP bits are set only for those Tx Buffers configured via TXBC. After a TXBRP bit has been set,
a Tx scan (see
with the highest priority (Tx Buffer with lowest Message ID).
A cancellation request resets the corresponding transmission request pending bit of register
TXBRP. In case a transmission has already been started when a cancellation is requested, this is
done at the end of the transmission, regardless whether the transmission was successful or not.
0:31
The cancellation request bits are reset directly after the corresponding TXBRP bit has been reset.
TRP
After a cancellation has been requested, a finished cancellation is signaled via TXBCF
– after successful transmission together with the corresponding TXBTO bit
– when the transmission has not yet been started at the point of cancellation
– when the transmission has been aborted due to lost arbitration
– when an error occurred during frame transmission
In DAR mode all transmissions are automatically cancelled if they are not successful. The
corresponding TXBCF bit is set for all unsuccessful transmissions.
0 No transmission request pending
1 Transmission request pending
Note: TXBRP bits which are set while a Tx scan is in progress are not considered during this
particular Tx scan. In case a cancellation is requested for such a Tx Buffer, this Add
Request is cancelled immediately, the corresponding TXBRP bit is reset.
1040/2058
2 3 4 5
0 0 0 0
19 20 21
0 0 0 0
Figure 504. Tx Buffer Request Pending register
Section 44.3.13.7: Tx Event
DocID027809 Rev 4
6 7 8 9
0 0 0 0
22 23 24 25
0 0 0 0
Description
handling) is started to check for the pending Tx request
10 11 12 13
0 0 0 0
26 27 28 29
0 0 0 0
RM0400
Access: R
14 15
0 0
30 31
0 0