UPD75218 NEC, UPD75218 Datasheet - Page 22

• Manufacturer Part Number: UPD75218
• Description: 4-BIT SINGLE-CHIP MICROCOMPUTER
• Manufacturer: NEC

P01/SCK
P02/SO
P03/SI
Notes 1. CMOS output and N-ch open-drain output switchable output buffer.
2. Instruction execution
SIO0
Note 1
Shift register (8)
8
8
Q
SO output
latch
Serial clock
counter (3)
Fig 5-7 Serial Interface Block Diagram
Clear
R
S
SIO7
SIO
Overflow
Internal bus
SIOM7 SIOM6 SIOM5 SIOM4 SIOM3 SIOM2 SIOM1 SIOM0
MPX
Serial start
8
SET1
f
f
XX
XX
Note 2
/2
/2
4
10
SIOM
IRQSIO
clear signal
INTSIO
IRQSIO
set signal