M16C65 Datasheet, PDF (600/829 Pages) Renesas Technology Corp – RENESAS MCU M16C FAMILY / M16C/60

Under development
M16C/65 Group
Preliminary Specification
This is a preliminary specification and is subject to change.
24. Serial Interface SI/O3 and SI/O4
24.3.8 Function for Setting SOUTi Initial Value
If the SMi6 bit in the SiC register is set to 0 (external clock), the SOUTi pin output can be fixed high or low
when not transmitting/receiving data. High or low can be selected by the SMi7 bit in the SiC register.
However, the last bit value of the previous unit of data is retained between adjacent units of data when
using external clock. Figure 24.7 shows Timing Chart for Setting SOUTi Initial Value and How to Set It.
(Example) When High Selected for SOUTi Initial Value
Write signal to
SiTRR register
SMi7 bit
SMi3 bit
Initial value setting of SOUTi output
and
starting of transmission/reception
Set the SMi3 bit to 0
(SOUTi pin functions as an I/O port)
SOUTi (internal)
D0
Set the SMi7 bit to 1
(SOUTi initial value = high)
Port output
SOUTi pin output
D0
Initial value = high
(i = 3, 4)
Setting the SOUTi Port selection switching
initial value to high ⁽¹⁾ (I/O port → SOUTi)
Set the SMi3 bit to 1
(SOUTi pin functions as SOUTi output)
High level is output from the SOUTi pin
Write into the SiTRR register
This diagram applies under the following conditions.
SMi2 = 0 (SOUTi output), SMi5 = 0 (LSB first), SMi6 = 0 (external clock)
Note:
1. SOUTi can only be initialized when input on the CLKi pin is in the high state if the
SMi4 bit in the SiC register = 0 (transmit data is output at the falling edge of the transmit
receive clock) or in the low state if the SMi4 bit = 1 (transmit data is output at the rising
edge of the transmit/receive clock).
Serial transmission/reception starts
Figure 24.7 Timing Chart for Setting SOUTi Initial Value and How to Set It
REJ09B0484-0030 Rev.0.30 Sep 09, 2008
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