SH7055S Datasheet, PDF (612/1002 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH RISC engine Family/SH7000 Series

HCAN sleep mode is entered by setting the HCAN sleep mode bit (MCR5) to 1 in the master
control register (MCR). If the CAN bus is operating, the transition to HCAN sleep mode is
delayed until the bus becomes idle.
Either of the following methods of clearing HCAN sleep mode can be selected by making a
setting in the MCR7 bit.
1. Clearing by software
2. Clearing by CAN bus operation
Eleven recessive bits must be received after HCAN sleep mode is cleared before CAN bus
communication is enabled again.
Clearing by Software: Clearing by software is performed by having the CPU write 0 to MCR5.
Clearing by CAN Bus Operation: Clearing by CAN bus operation occurs automatically when
the CAN bus performs an operation and this change is detected. In this case, the first message is
not received in the message box; normal reception starts with the second message. When a change
is detected on the CAN bus in HCAN sleep mode, the bus operation interrupt flag (IRR12) is set
in the interrupt register (IRR). If the bus interrupt mask (IMR12) in the interrupt mask register
(IMR) is set to the interrupt enable value at this time, an interrupt can be sent to the CPU.
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