h8s-2649 Renesas Electronics Corporation., h8s-2649 Datasheet - Page 497

• Manufacturer Part Number: h8s-2649
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

Section 14 Controller Area Network (HCAN)
Message transmission cancellation: Transmission cancellation can be specified for a message
stored in a mailbox as a transmit wait message. A transmit wait message is canceled by setting the
bit for the corresponding mailbox (TXCR1 to TXCR15) to 1 in the transmit cancel register
(TXCR). Clearing the transmit wait register (TXPR) does not cancel transmission. When
cancellation is executed, the transmit wait register (TXPR) is automatically reset, and the
corresponding bit is set to 1 in the abort acknowledge register (ABACK), and then an interrupt to
the CPU can be requested. Also, if the corresponding bit (MBIMR1-MBIMR15) in the mailbox
interrupt mask register (MBIMR) and the mailbox empty interrupt bit (IRR8) in the interrupt mask
register (IMR) are both simultaneously set to enable interrupts, interrupts may be sent to the CPU.
However, a transmit wait message cannot be canceled at the following times:
• During internal arbitration or CAN bus arbitration
• During data frame or remote frame transmission
Figure 14.10 shows a flowchart for transmit message cancellation.
Rev. 2.00 Dec. 05, 2005 Page 459 of 724
REJ09B0200-0200