SH7760 Datasheet, PDF (866/1345 Pages) Renesas Technology Corp – SuperHTM RISC engine

• CANTXCR is set (not that, if CANTXCR is set for the message currently under transmission,
HCAN2 does not stop the transmission but completes. If the message loses the bus arbitration
or causes an error on the bus, the HCAN2 will cancel the transmission request.)
• Error occurs on the CAN bus.
• Message under transmission loses the arbitration on the CAN bus.
• Mailbox with the setting of MBC = B’001 receives a Remote Frame.
Whenever these factors happen, the internal arbitration starts running to ensure that the highest
priority message is always transmitted first. The followings are examples set in the diagram.
1-1
: When a TXPR bit(s) is set while the CAN bus is idle, the internal arbitration starts
running immediately and the transmission is started.
2-1, 2-2 : During this period (Tx Arb for Frame-2), whenever or however many times any of
the 4 factors occurs, the internal arbitration starts running and scheduled for the next
frame (Frame-2) to be transmitted.
3-1, 3-2 : During this period (Rx Matching), any internal arbitration is not allowed to run, but
scheduled later at the SOF of the next frame (Frame-2). If the transmit-requested
message has the highest priority, the transmission will be set for the Frame-3.
3-3, 3-4 : This is the same case as 2-1,2-2.
Rev. 1.0, 02/03, page 816 of 1294