Philips CEM2100/00 Service Manual page 301

Serial Interface Status Register
7 6
SIO2SR
(0032H)
SIOF SEF
Serial transfer operation status
SIOF
monitor
SEF Number of clocks monitor
TXF Transmit buffer empty flag
RXF Receive buffer full flag
TXERR Transfer operation error flag
RXERR Receive operation error flag
Note 1: The operation error flag (TXERR and RXERR) are not automatically cleared by stopping transfer with SIO2CR<SIOS>
"0". Therefore, set these bits to "0" for clearing these error flag. Or set SIO2CR<SIOINH> to "1".
Note 2: *: Don't care
Receive buffer register
7 6
SIO2RDB
(002BH)
Transmit buffer register
7 6
SIO2TDB
(002BH)
Note 1: SIO2TDB is write only register. A bit manipulation should not be performed on the transmit buffer register using a read-
modify-write instruction.
Note 2: The SIO2TDB should be written after checking SIO2SR<TXF> "1". When SIO2SR<TXF> is "0", the writing data can't be
transferred to SIO2TDB even if write instruction is executed to SIO2TDB .
Note 3: *: Don't care
5 4 3 2
TXF RXF TXERR RXERR
0: Transfer finished
1: Transfer in progress
0: 8 clocks
1: 1 to 7 clocks
0: Data exists in transmit buffer
1: No data exists in transmit buffer
0: No data exists in receive buffer
1: Data exists in receive buffer
Read
0: – (No error exist)
1: Transmit buffer under run occurs in an external clock mode
Write
0: Clear the flag
1: – (A write of "1" to this bit is ignored)
Read
0: – (No error exist)
1: Receive buffer over run occurs in an external clock mode
Write
0: Clear the flag
1: – (A write of "1" to this bit is ignored)
5 4 3 2
5 4 3 2
Page 179
1 0
(Initial value: 0010 00**)
1 0 Read only
(Initial value: 0000 0000)
1 0 Write only
(Initial value: **** ****)
T5CL8
Read
only
R/W