SH7055S Datasheet, PDF (600/1002 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH RISC engine Family/SH7000 Series

Initialization (after Hardware Reset Only): These settings should be made while the HCAN is
in bit configuration mode.
1. IRR0 clearing
The reset interrupt flag (IRR0) is always set after a power-on reset or recovery from software
standby mode. As an HCAN interrupt is initiated immediately when interrupts are enabled,
IRR0 should be cleared.
2. HCAN pin port settings
To prevent erroneous identification of CAN bus data, HCAN pin port settings should be made
first. See HCAN Pin Port Settings in section 16.3.2, Initialization after a Hardware Reset, and
section 20, Pin Function Controller, for details.
3. Bit rate settings
Set values relating to the CAN bus communication speed and re-synchronization. See Bit Rate
Settings in section 16.3.2, Initialization after a Hardware Reset, for details.
4. Mailbox transmit/receive settings
Mailbox transmit/receive settings should be made in advance. A total of 30 mailbox can be set
for transmission or reception (mailboxes 1 to 15 in HCAN0 and HCAN1). To set a mailbox for
transmission, clear the corresponding bit to 0 in the mailbox configuration register (MBCR).
See Mailbox Transmit/Receive Settings in section 16.3.2, Initialization after a Hardware Reset,
for details.
5. Mailbox initialization
As message control/data registers (MCx[x], MDx[x]) are configured in RAM, their initial
values after powering on are undefined, and so bit initialization is necessary. Write 0s or 1s to
the mailboxes. See Mailbox (Message Control/Data (MCx[x], MDx[x]) Initial Settings in
section 16.3.2, Initialization after a Hardware Reset, for details.
6. Message transmission method setting
Set the transmission method for mailboxes designated for transmission. The following two
transmission methods can be used. See Setting the Message Transmission Method in section
16.3.2, Initialization after a Hardware Reset, for details.
a. Transmission order determined by message identifier priority
b. Transmission order determined by mailbox number priority
Rev.2.0, 07/03, page 562 of 960