h8s-2646 Renesas Electronics Corporation., h8s-2646 Datasheet - Page 605

• Manufacturer Part Number: h8s-2646
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

Initialization (After Hardware Reset Only): These settings should be made while the HCAN is
in bit configuration mode.
• IRR0 clearing
• Bit rate settings
• Mailbox transmit/receive settings
• Mailbox initialization
• Message transmission method setting
The reset interrupt flag (IRR0) is always set after a reset or recovery from software standby
mode. A HCAN interrupt is immediately entered if interrupts are enabled, so that IRR0 must
be cleared.
Set values relating to the CAN bus communication speed and resynchronization. Refer to Bit
Rate and Bit Timing Settings in section 15.3.2, Initialization after Hardware Reset, for details.
Mailbox transmit/receive settings should be made in advance. A total of 15 mailbox can be set
for transmission or reception (mailboxes 1 to 15). To set a mailbox for transmission, clear the
corresponding bit to 0 in the mailbox configuration register (MBCR). Refer to Mailbox
transmit/receive settings in section 15.3.2, Initialization after Hardware Reset, for details.
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. Refer to Mailbox (message control/data (Mcx[x], Mdx[x])) initial settings in
section 15.3.2, Initialization after Hardware Reset, for details.
Set the transmission method for mailboxes designated for transmission. The following two
transmission methods can be used. Refer to Message transmission method settings in section
15.3.2, Initialization after Hardware Reset, for details.
a. Transmission order determined by message identifier priority
b. Transmission order determined by mailbox number priority
Section 15 Controller Area Network (HCAN)
Rev. 5.00 Sep 22, 2005 page 579 of 1136
REJ09B0257-0500