upd70f3422gj-gae-qs-ax Renesas Electronics Corporation., upd70f3422gj-gae-qs-ax Datasheet - Page 727

• Manufacturer Part Number: upd70f3422gj-gae-qs-ax
• Description: 32-bit Single-chip Microcontroller
• Manufacturer: Renesas Electronics Corporation.

CAN Controller (CAN)
Status of TRQ of
ABT message buffer
Set (1)
Cleared (0)
19.11.4 Transmission abort process
19.11.5 Remote frame transmission
Note
(1)
(2)
Transmission abort in normal operation mode
The user can clear the CnMCTRLm.TRQ bit to 0 to abort a transmission
request. The TRQ bit will be cleared immediately if the abort was successful.
Whether the transmission was successfully aborted or not can be checked
using the CnCTRL.TSTAT bit and the CnTGPT register, which indicate the
transmission status on the CAN bus (for details, refer to the processing in
Figure 19-43 on page 754).
Transmission abort in normal operation mode with automatic block
transmission (ABT)
To abort ABT that is already started, clear the CnGMABT.ABTTRG bit to 0. In
this case, the ABTTRG bit remains 1 if an ABT message is currently being
transmitted and until the transmission is completed (successfully or not), and is
cleared to 0 as soon as transmission is finished. This aborts ABT.
If the last transmission (before ABT) was successful, the normal operation
mode with ABT is left with the internal ABT pointer pointing to the next
message buffer to be transmitted.
In the case of an erroneous transmission, the position of the internal ABT
pointer depends on the status of the TRQ bit in the last transmitted message
buffer. If the TRQ bit is set to 1 when clearing the ABTTRG bit is requested, the
internal ABT pointer points to the last transmitted message buffer (for details,
refer to the process in Figure 19-44 on page 755).
When the normal operation mode with ABT is resumed after ABT has been
aborted and the ABTTRG bit is set to 1, the next ABT message buffer to be
transmitted can be determined from the following table.
The above resumption operation can be performed only if a message buffer
ready for ABT exists in the ABT area. For example, an abort request that is
issued while ABT of message buffer 7 is in progress is regarded as completion
of ABT, rather than abort, if transmission of message buffer 7 has been
successfully completed, even if the ABTTRG bit is cleared to 0. If the
CnMCTRLm.RDY bit in the next message buffer in the ABT area is cleared to
0, the internal ABT pointer is retained, but the resumption operation is not
performed even if the ABTTRG bit is set to 1, and ABT ends immediately.
Remote frames can be transmitted only from transmit message buffers. Set
whether a data frame or remote frame is transmitted via the CnMCONFm.RTR
bit. Setting (1) the RTR bit sets remote frame transmission.
Preliminary User’s Manual U17566EE1V2UM00
Abort after successful transmission
Next message buffer in the ABT area
Next message buffer in the ABT area
Note
Note
Abort after erroneous transmission
Same message buffer in the ABT area
Next message buffer in the ABT area
Chapter 19
Note
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