UPD75518 NEC, UPD75518 Datasheet - Page 109

• Manufacturer Part Number: UPD75518
• Description: 4 BIT SINGLE-CHIP MICROCOMPUTER
• Manufacturer: NEC

Slave device processing (transmitter)
Master device processing (receiver)
Transfer line
Program processing
Program processing
Hardware operation
Hardware operation
SCK0 pin
SB0 pin
BUSY
Write
to SIO0
Clear
BUSY
READY
Stop
SCK0
Fig. 4-52 Data Transmission from Master Device to Slave Device
Write FFH
to SIO0
1
D7
2
D6
3
D5
Serial reception
Serial transmission
4
D4
Data
5
D3
6
D2
7
D1
8
D0
9
Generate
IRQCSI0
Generate
IRQCSI0
Read
SIO0
Write
FFH to
SIO0
Output
ACK
Set
ACKT
ACK
Set
ACKD
Receive data processing
BUSY
Output
BUSY
Write
to SIO0
Clear
BUSY
READY
1
Serial reception
D7
2
D6