Reading Out Received Data Frames When Set For Remote Frame Transmission - Mitsubishi Electric M32R Series User Manual

Mitsubishi 32-bit risc single-chip microcomputers

Table of Contents

13.7.3 Reading Out Received Data Frames when Set for Remote Frame Transmission

The following describes the procedure for reading out received data frames from the slot when it is

set for remote frame transmission.

(1) Clearing the TRFIN (Transmit/Receive Finished) bit

Write H'AE or H'00 to the CAN Message Control Register (C0MSLnCNT) to clear the TRFIN bit to

0. After this write, the slot operates as follows:

Value written to

Note 1: If message-lost check by the ML bit is needed, write H'AE to the C0MSLnCNT register as

you clear the TRFIN bit.

Note 2: If you clear the TRFIN bit by writing H'AE or H'00, it is possible that new data will be

stored in the slot while still reading a message from the slot.

Note 3: The received data frame cannot be read out by writing H'A0 to the register. If you clear

the TRFIN bit by writing H'A0, the slot performs remote frame transmit operation.

(2) Reading out from the message slot

Read out a message from the message slot.

(3) Checking the TRFIN (Transmit/Receive Finished) bit

Read the CAN Message Control Register to check the TRFIN (Transmit/Receive Finished) bit.

When TRFIN (Transmit/Receive Finished) bit = 1

It means that new data was stored in the slot while still reading out from the slot in (2). In this

case, the data read out in (2) may contain an indeterminate value. Therefore, reexecute

beginning with clearing of the TRFIN (Transmit/Receive Finished) bit in (1).

When TRFIN (Transmit/Receive Finished) bit = 0

It means that the CAN module finished reading out from the slot normally.

Slot operation after write

Operates as a data frame receive slot.

Overwrite can be verified by ML bit.

The slot stops transmit/receive operation.

13.7 Transmitting Remote Frames