13.8.10 Hcan Transmission Setting; 13.8.11 Canceling Hcan Reset And Hcan Sleep Mode; 13.8.12 Accessing Mailbox In Hcan Sleep Mode; Table 13.5 Duration Between Transmission Setting - Renesas H8SX/1520 Series Hardware Manual

13.8.10 HCAN Transmission Setting

With the following conditions satisfied, a previous message identifier (ID) may be collapsed when
the next transmission is set or transmission is canceled within 50 µs after the previous
transmission has been set in the bus idle state.
• When the message set at the second transmission setting has priority over the message set at
the first transmission setting
• When the message canceled at the first transmission setting has priority over any messages
The following settings should be performed so that a message ID is not collapsed.
• Transmission setting should be performed at a time. The next transmission setting should be
set at least 50 µs after completion of transmission of all messages (en bloc transmission).
• Transmission setting should be performed according to the priority.
• Sufficient duration should be taken between transmission setting or cancellation: setting TXPR
and setting TXPR or setting TXPR and setting TXCR.

Table 13.5 Duration between Transmission Setting

Baud Rate (bps)
1 M
500 k
250 k

13.8.11 Canceling HCAN Reset and HCAN Sleep Mode

Before canceling an HCAN software reset or HCAN sleep mode (clearing bit MCR0 or MCR5
to 0), confirm that the reset status bit (GSR3) has been set to 1.

13.8.12 Accessing Mailbox in HCAN Sleep Mode

Do not access any Mailbox in HCAN sleep mode. When the access is attempted, the CPU may
stop operating.
Accessing registers does not cause the CPU to halt. Accessing a Mailbox in other than HCAN
sleep mode does not cause the CPU to halt.
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Section 13 Controller Area Network (HCAN)
Setting Interval (µs)
50
50
50
Rev. 3.00 Mar. 14, 2006 Page 507 of 804
REJ09B0104-0300