HD404318 Datasheet, PDF (45/68 Pages) Hitachi Semiconductor – 4-bit HMCS400-series microcomputer

SO
SCK
SI
Idle
controller
I/O
controller
Octal
counter (OC)
Clock
1/2
1/2
HD404318 Series
Serial interrupt
request flag
(IFS)
Serial data
register (SR)
Transfer
control
signal
System
clock
ø_PER
Selector
3
Serial mode
register
(SMR)
Prescaler S (PSS)
Port mode
register C
(PMRC)
Figure 33 Serial Interface Block Diagram
43