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Chapter 19
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Transmission of a data frame from an ABT message buffer is not recorded in
the transmit history list (THL).
Caution
1.
Set the ABTCLR bit to 1 while the ABTTRG bit is cleared to 0. If the
ABTCLR bit is set to 1 while the ABTTRG bit is set to 1, the subsequent
operation is not guaranteed.
2.
If the automatic block transmission engine is cleared by setting the ABTCLR
bit to 1, the ABTCLR bit is automatically cleared immediately after the
processing of the clearing request is completed.
3.
Do not set the ABTTRG bit in the initialization mode. If the ABTTRG bit is
set in the initialization mode, the proper operation is not guaranteed after the
mode is changed from the initialization mode to the ABT mode.
4.
Do not set the TRQ bit of the ABT message buffers to 1 by software in the
normal operation mode with ABT. Otherwise, the operation is not
guaranteed.
5.
The CnGMABTD register is used to set the delay time that is inserted in the
period from completion of the preceding ABT message to setting of the TRQ
bit for the next ABT message when the transmission requests are set in the
order of message numbers for each message for ABT that is successively
transmitted in the ABT mode. The timing at which the messages are actually
transmitted onto the CAN bus varies depending on the status of
transmission from other stations and the status of the setting of the
transmission request for messages other than the ABT messages (message
buffers 8 to 31).
6.
If a transmission request is made for a message other than an ABT
message and if no delay time is inserted in the interval in which
transmission requests for ABT are automatically set (CnGMABTD register =
00H), messages other than ABT messages are transmitted. At this time,
transmission does not depend on the priority of the ABT message.
7.
Do not clear the RDY bit to 0 when the ABTTRG bit = 1.
8.
If a message is received from another node in the normal operation mode
with ABT, the message may be transmitted after the time of one frame has
elapsed (when CnGMABTD register = 00H).
Preliminary User's Manual U17566EE1V2UM00
CAN Controller (CAN)
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