UPD75518 NEC, UPD75518 Datasheet - Page 108

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

Master device processing (transmitter)
Transfer line
Slave device processing (receiver)
Program processing
Program processing
Hardware operation
Hardware operation
SCK0 pin
SB0 pin
Fig. 4-51 Data Transmission from Master Device to Slave Device
Write
to SIO0
1
D7
2
D6
3
D5
Serial transmission
4
Serial reception
D4
Data
5
D3
6
D2
7
D1
8
D0
9
Generate
IRQCSI0
Generate
IRQCSI0
Read
SIO0
Interrupt handling (preparation for next serial transfer)
Set
ACKT
Output
ACK
Output
BUSY
ACK
Set
ACKD
BUSY
Clear
BUSY
Clear
BUSY
READY
Stop
SCK0