NEC UPD789426 Series User Manual page 248

(x) Master operation (when DAP20 = 1, CKP20 = 1, SSE20 = 0)
SIO20
write
SCK20
1
SO20
Note
SI20
INTCSI20
Note The value of the last bit previously output is output.
(xi) Slave operation (when DAP20 = 1, CKP20 = 1, SSE20 = 0)
SIO20
write
SCK20
1
SI20
Note
SO20
INTCSI20
Note The value of the last bit previously output is output.
CHAPTER 12 SERIAL INTERFACE 20
Figure 12-11. 3-Wire Serial I/O Mode Timing (6/7)
2 3
DO7 DO6 DO5
DI7 DI6 DI5
2 3
DI7 DI6 DI5
DO7 DO6 DO5
User's Manual U15075EJ2V1UD
4 5 6
DO4 DO3 DO2
DI4 DI3 DI2
4 5 6
DI4 DI3 DI2
DO4 DO3 DO2
7 8
DO1 DO0
DI1 DI0
7 8
DI1
DI0
DO1 DO0
249