
CHAPTER 9 SERIAL INTERFACE 10
User’s Manual U12978EJ3V0UD
158
Table 9-2. Operating Mode Settings of Serial Interface 10
(1) Operation stop mode
CSIM10
PM22
P22
PM21
P21
PM20
P20
Start
Shift
P22/SI10
P21/SO10
P20/SCK10
CSIE10
DIR10
CSCK10
Bit
Clock
Pin Function
Pin Function
Pin Function
0
×
×
×
Note 1
×
Note 1
×
Note 1
×
Note 1
×
Note 1
×
Note 1
—
—
P22
P21
P20
Other than above
Setting prohibited
(2) 3-wired serial I/O mode
CSIM10
PM22
P22
PM21
P21
PM20
P20
Start
Shift
P22/SI10
P21/SO10
P20/SCK10
CSIE10
DIR10
CSCK10
Bit
Clock
Pin Function
Pin Function
Pin Function
1
0
0
1
Note 2
×
Note 2
0
1
1
×
MSB
External
clock
SI10
Note 2
SO10
(CMOS output)
SCK10 input
1
0
1
Internal
clock
SCK10 output
1
1
0
1
×
LSB
External
clock
SCK10 input
1
0
1
Internal
clock
SCK10 output
Other than above
Setting prohibited
Notes 1.
Can be used as port function.
2.
If used only for transmission, can be used as P22 (CMOS input/output).
Remark
×
: don’t care