CHAPTER 10 SERIAL INTERFACE FUNCTION
User’s Manual U13850EJ6V0UD
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10.2.3 Operations
CSIn has the following two operation modes.
•
Operation stop mode
•
3-wire serial I/O mode
(1) Operation stop mode
Serial transfers are not performed in this mode, enabling a reduction in power consumption.
In operation stop mode, if SIn, SOn, and SCKn pin are also used as I/O ports, they can be used as normal I/O
ports as well.
(a) Register settings
Operation stop mode is set via the CSIEn bit of serial operation mode register n (CSIMn).
Figure 10-2. CSIMn Setting (Operation Stop Mode)
After reset : 00H
R/W
Address: CSIM0
FFFFF2A2H
CSIM1
FFFFF2B2H
CSIM2
FFFFF2C2H
CSIM3
FFFFF2D2H
7
6
5
4
3
2
1
0
CSIMn
CSIEn
0
0
0
0
MODEn
SCLn1
SCLn0
(n = 0 to 3)
SIOn operation enable/disable specification
CSIEn
Shift register operation
Serial counter
Port
0
Operation disable
Clear
Port function