upd75238 Renesas Electronics Corporation., upd75238 Datasheet - Page 105

• Manufacturer Part Number: upd75238
• Description: 4 Bit Single-chip Microcomputer
• Manufacturer: Renesas Electronics Corporation.

Master device processing (receiver)
Transfer line
Slave device processing (transmitter)
Program processing
Program processing
Hardware operation
Hardware operation
SCK0 pin
SB0 pin
BUSY
Write
to SIO0
Clear
BUSY
READY
Fig. 4-57 Data Transfer Operation from Master Device to Slave Device
Stop
SCK0
Write FFH
to SIO0
1
D7
2
D6
3
Serial receive operation
D5
Serial send operation
4
D4
Data
5
D3
6
D2
7
D1
8
D0
9
Generate
Generate
IRQCSI0
IRQCSI0
Read
SIO0
Output
ACK
Set
ACKT
ACK
Write FFH
to SIO0
Set
ACKD
BUSY
Output
BUSY
Receive data processing
Write
to SIO0
Clear
BUSY
READY
1
Serial reception
D7
2
D6