UPD75518 NEC, UPD75518 Datasheet - Page 107

• 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. 4-50 Command Transmission from Master Device to Slave Device
Set
CMDT
Set
CMDD
Write
to SIO0
1
C7
2
C6
3
C5
Serial transmission
Command
4
Serial reception
C4
5
C3
6
C2
7
C1
8
C0
9
Generate
IRQCSI0
Generate
IRQCSI0
Read
SIO0
Interrupt handling (preparation for next serial transfer)
Analyze
command
Set
ACKT
Output
ACK
Output
BUSY
ACK
Set
ACKD
BUSY
Clear
BUSY
Clear
BUSY
READY
Stop
SCK0