Philips CEM2100/00, Service Manual

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Page 170
14. Synchronous Serial Interface (SIO1)
14.3 Function
T
5CL8
Figure 14-11 Example of External Clock and MSB Receive Mode
(4) Receive error processing
Receive errors occur on the following situation. To protect SIO1RDB and the shift register con-
tents, the received data is ignored while the SIO1SR<RXERR> is “1”.
• Shift operation is finished before reading out received data from SIO1RDB at
SIO1SR<RXF> is “1” in an external clock operation.
If receive error occurs, set the SIO1CR<SIOS> to “0” for reading the data that received
immediately before error occurence. And read the data from SIO1RDB. Data in shift register
(at errors occur) can be read by reading the SIO1RDB again.
When SIO1SR<RXERR> is cleared to “0” after reading the received data, SIO1SR<RXF> is
cleared to “0”.
After clearing SIO1CR<SIOS> to “0”, when 8-bit serial clock is input to
SCK1
pin, receive
operation is stopped. To restart the receive operation, confirm that SIO1SR<SIOF> is cleared
to “0”.
If the receive error occurs, set the SIO1CR<SIOINH> to “1” for stopping the receive opera-
tion immediately. In this case, SIO1CR<SIOS>, SIO1SR register, SIO1RDB register and
SIO1TDB register are initialized.
Writing transmit
data C
Writing transmit
data B
Writing transmit
data A
C B
A7 A6
A
A5 A4 A3 A2 A1 A0 B7 B6 B5 B4 B3 B2 B1 B0 C7 C6 C5 C4 C3 C2 C1 C0
Start shift
operation
Start shift
operation
Start shift
operation
Clearing SIOS Reading received data
SIO1CR<SIOS>
SIO1SR<SIOF>
SIO1SR<SEF>
SCK1
pin
SI1 pin
SIO1SR<RXF>
INTSIO1
interrupt
request
SIO1RDB