
58
EPSON
S1C8F626 TECHNICAL MANUAL
5 PERIPHERAL CIRCUITS AND THEIR OPERATION (Serial Interface)
■ Data receive procedure
The control procedure and operation during
receiving is as follows.
(1) Write "0" in the receive enable register RXENx
and transmit enable register TXENx to reset the
serial interface.
(2) Write "1" in the receive enable register RXENx
to set into the receiving enable status.
(3) In case of the master mode, confirm the transmit
ready status on the slave side (external serial
input/output device), if necessary. Wait until it
reaches the transmit ready status.
(4) Write "1" in the receive control bit RXTRGx and
start receiving.
In the master mode, this control causes the
synchronous clock to change to enable and is
provided to the shift register for receiving and
_________
output from the SCLKx terminal.
In the slave mode, it waits for the synchronous
_________
clock to be input from the SCLKx terminal. The
received data input from the SINx terminal is
successively incorporated into the shift register
in synchronization with the rising edge of the
synchronous clock.
At the point where the data of the 8th bit has
been incorporated at the final (8th) rising edge
of the synchronous clock, the content of the shift
register is sent to the received data buffer and
the receiving complete interrupt factor flag
FSRECx is set to "1". When interrupt has been
enabled, a receiving complete interrupt is
generated at this point.
(5) Read the received data from TRXDx0–TRXDx7
using receiving complete interrupt.
(6) Repeat steps (3) to (5) for the number of bytes of
receiving data, and then set the receive disable
status by writing "0" to the receive enable
register RXENx, when the receiving is com-
pleted.
Data receiving
End
RXENx
← 0, TXENx ← 0
No
Yes
Receiving complete ?
Received data reading
from TRXDx0–TRXDx7
No
Yes
FSRECx = 1 ?
RXENx
← 0
RXTRGx
← 1
RXENx
← 1
No
Yes
Transmitter ready ?
In case of master mode
Fig. 5.7.6.3 Receiving procedure in clock synchronous mode