Lucent Technologies MN102F75K Manuale Utente

142

SC0STR/SC1STR: Serial Port n Status Register

SCnSTR contains the error detection and status flags for the serial inter-
faces.

SCnTBY: Serial port n transmission busy flag

0: OK to transmit

1: Transmission in progress

SCnRBY: Serial port n reception busy flag

0: OK to receive

1: Reception in progress

SCnISP: Serial port n I

2

C stop sequence detect

A read or write to SCnTRB clears this bit.

0: No stop sequence

1: Stop sequence detected

SCnRXA: Serial port n received data flag

0: Not received

1: Received

SCnIST: Serial port n I

2

C start sequence detect

A read or write to SCnTRB clears this bit.

0: No start sequence

1: Start sequence detected

SCnFE: Serial port n framing error

A framing error occurs when a 0 is received during stop bit transfer. Fram-
ing error data is updated each time the stop bit is received.

0: No error
1: Framing error occurred

SCnPE: Serial port n parity error

A parity error occurs when the received parity bit is 1 and the parity setting 
is 0; when the received parity bit is 0 and the parity setting is 1; when the 

received parity bit is odd and the parity setting is even; or when the 
received parity bit is even and the parity setting is odd. Parity error data is 

updated each time the parity bit is received.

0: No error

1: Parity error occurred

SCnOE: Serial port n overrun error

An overrun error occurs during reception when a data byte reception ends 
before the CPU has read the previous byte from SCnTRB. Overrun error 

data is updated each time the last data bit (seventh or eighth bit) is received.

0: No error

1: Overrun error occurred

Bit:

7

6

5

4

3

2

1

0

SCn

TBY

SCn

RBY

SCn

ISP

SCn

RXA

SCn

IST

SCn

FE

SCn

PE

SCn

OE

Reset:

0

0

0

0

0

0

0

0

R/W:

R

R

R

R

R

R

R

R