Transmitting Data Frames; Data Frame Transmit Procedure - Mitsubishi Electric M32R Series User Manual

Mitsubishi 32-bit risc single-chip microcomputers

Table of Contents

13.5 Transmitting Data Frames

The following describes the procedure for transmitting data frames.

(1) Initializing the CAN Message Slot Control Register

Initialize the CAN Message Slot Control Register for the slot in which you want to transmit by

writing H'00 to the register.

(2) Confirming that transmission is idle

Read the CAN Message Slot Control Register after being initialized and check the TRSTAT

(Transmit/Receive Status) bit to see that transmission has stopped and remains idle. If this bit =

1, it means that the CAN module is accessing the message slot, so you need to wait until the bit

(3) Setting transmit data

Set the transmit ID and transmit data in the message slot.

(4) Setting the Extended ID Register

Set the corresponding bit of the Extended ID Register to 0 when you want to transmit the data as

a standard frame or 1 when you want to transmit the data as an extended frame.

(5) Setting the CAN Message Slot Control Register

Write H'80 (note) to the CAN Message Slot Control Register to set the TR (Transmit Request) bit

Note: When you are transmitting a data frame, always write H'80 to this register.

13.5 Transmitting Data Frames