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11 transmission request register (treqr), Register function – FUJITSU F2MCTM-16LX User Manual

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21.4.11

Transmission Request Register (TREQR)

Transmission request register (TREQR) stores transmission requests to the message
buffers (x) or displays their state.

Register Configuration

Figure 21.4-11 Configuration of the Transmission Request Register (TREQR)

Register Function

When 1 is written to TREQx, transmission to the message buffer (x) starts.

If RFWTx of the remote frame receiving wait register (RFWTR)

*1

is 0, transmission starts immediately.

However, if RFWTx = 1, transmission starts after waiting until a remote frame is received (RRTRx of the

remote request receiving register (RRTRR)

*1

becomes 1). Transmission starts

*2

immediately even when

RFWTx = 1, if RRTRx is already 1 when 1 is written to TREQx.

*1: For RFWTR and TRTRR, see "21.4.12 Transmission RTR Register (TRTRR)" and "21.4.13 Remote

Frame Receiving Wait Register (RFWTR)".

*2: For cancellation of transmission, see "21.4.14 Transmission Cancel Register (TCANR)" and "21.4.15

Transmission Complete Register (TCR)".

Writing 0 to TREQx is ignored.

0 is read when a Read Modify Write instruction is performed.

If clearing (to 0) at completion of the transmit operation and setting by writing 1 are concurrent, clearing is

preferred.

If 1 is written to more than 1 bit, transmission is performed, starting with the lower-numbered message

buffer (x).

TREQx is 1 while transmission is pending, and becomes 0 when transmission is completed or canceled.

Address

bit15

bit14

bit13

bit12

bit11

bit10

bit9

bit8

TREQR1(Upper)

CAN1:

000083

H

TREQ15

TREQ14

TREQ13

TREQ12

TREQ11

TREQ10

TREQ9

TREQ8

Reset value
0 0 0 0 0 0 0 0

B

R/W

R/W

R/W

R/W

R/W

R/W

R/W

R/W

Address

bit7

bit6

bit5

bit4

bit3

bit2

bit1

bit0

TREQR1(Lower)

CAN1:

000082

H

TREQ7

TREQ6

TREQ5

TREQ4

TREQ3

TREQ2

TREQ1

TREQ0

Reset value
0 0 0 0 0 0 0 0

B

R/W

R/W

R/W

R/W

R/W

R/W

R/W

R/W

R/W : Read/Write