NEC 78K0 User Manual page 306

The relationship between the register settings and pins is shown below.
Table 14-2. Relationship Between Register Settings and Pins
CSIE10 TRMD10 PM11
Note 1
0 × ×
1 0 1
Note 1
1 1 ×
1 1 1
1 0 1
Note 1
1 1 ×
1 1 1
Notes 1. Can be set as port function.
2. To use P10/SCK10/TxD0 as port pins, clear CKP10 to 0.
3. To use the slave mode, set CKS102, CKS101, and CKS100 to 1, 1, 1.
Remark ×:
CSIE10:
TRMD10:
CKP10:
CKS102, CKS101, CKS100: Bits 2 to 0 of CSIC10
PM1×:
P1×:
306
CHAPTER 14 SERIAL INTERFACE CSI10
P11 PM12 P12 PM10
Note 1 Note 1 Note 1 Note 1
× × × ×
Note 1 Note 1
× × × 1
Note 1
× 0 0 1
× 0 0 1
Note 1 Note 1
× × × 0
Note 1
× 0 0 0
× 0 0 0
don't care
Bit 7 of serial operation mode register 10 (CSIM10)
Bit 6 of CSIM10
Bit 4 of serial clock selection register 10 (CSIC10)
Port mode register
Port output latch
User's Manual U16227EJ2V0UD
P10 CSI10
Operation
SI10/RxD0/
Note 1
× Stop RxD0/P11
× Slave
Note 3
reception
× Slave RxD0/P11
Note 3
transmission
× Slave
transmission/
Note 3
reception
1 Master reception
1 Master RxD0/P11
transmission
1 Master
transmission/
reception
Pin Function
SO10/P12 SCK10/
P11 TxD0/P10
P12 TxD0/
Note 2
P10
SI10 P12 SCK10
Note 3
(input)
SO10 SCK10
Note 3
(input)
SI10 SO10 SCK10
Note 3
(input)
SI10 P12 SCK10
(output)
SO10 SCK10
(output)
SI10 SO10 SCK10
(output)