MSM80C154S/83C154S

 

 

 

 

 

 

 

 

 

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Serial port control register (SCON)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NAME

ADDRESS

MSB

 

 

 

 

 

 

 

 

 

 

 

LSB

7

 

6

 

5

4

 

3

 

2

 

1

 

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SCON

98H

SM0

 

SM1

 

SM2

REN

 

TB8

 

RB8

 

TI

 

RI

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

BIT LOCATION

FLAG

 

 

 

 

 

FUNCTION

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SCON.0

RI

"End of serial port reception" interrupt request flag.

 

 

 

 

 

 

 

This flag must be reset by software during interrupt service routine.

 

 

 

This flag is set after the eighth bit of data has been received when in mode 0, or

 

 

by the STOP bit when in any other mode.

 

 

 

 

 

 

 

 

 

In mode 2 or 3, however, RI is not set if the RB8 data is "0" with SM2 = "1".

 

 

 

RI is set in mode 1 if STOP bit is received when SM2 = "1".

 

 

 

 

 

 

 

 

 

 

 

 

 

SCON.1

TI

"End of serial port tramsmission" interrupt request flag. This flag must be reset

 

 

by software during interrupt service routine.

 

 

 

 

 

 

 

This flag is set after the eighth bit of data has been sent when in mode 0, or after

 

 

the last bit of data has been sent when in any other mode.

 

 

 

 

 

 

 

 

 

SCON.2

RB8

The ninth bit of data received in mode 2 or 3 is passed to RB8.

 

 

 

 

 

The STOP bit is applied to RB8 if SM2 = "0" when in mode 1.

 

 

 

 

 

RB8 can not be used in mode 0.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SCON.3

TB8

The TB8 data is sent as the ninth data bit when in mode 2 or 3.

 

 

 

 

 

Any desired data can be set in TB8 by software.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SCON.4

REN

Reception enable control bit.

 

 

 

 

 

 

 

 

 

 

 

No reception when REN = "0".

 

 

 

 

 

 

 

 

 

 

 

Reception enabled when REN = "1".

 

 

 

 

 

 

 

 

 

 

SCON.5

SM2

If the ninth bit of received data is "0" with SM2 = "1" in mode 2 or 3, the "end of

 

 

reception" signal is not set in the RI flag.

 

 

 

 

 

 

 

 

 

The "end of reception" signal set in the RI flag if the STOP bit is not "1" when

 

 

 

SM2 = "1" in mode 1.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SCON.6

SM1

SM0

SM1

MODE

 

 

 

 

 

 

 

 

 

 

 

0

 

0

 

0

8-bit shift register I/O

 

 

 

 

 

 

 

0

 

1

 

1

8-bit UART variable baud rate

 

 

 

 

 

 

 

 

 

 

9-bit UART 1/32 XTAL1, 1/64 XTAL1 baud rate

SCON.7

SM0

1

 

0

 

2

 

 

1

 

1

 

3

9-bit UART variable baud rate

 

 

 

272

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Image 14
Oki MSM80C154S, MSM83C154S manual Serial port control register Scon, Ren, Mode