NEC PD750008 - Manual (Page 192)

172
µPD750008 USER'S MANUAL
Figure 5-70. Data Transfer Operation from Slave Device to Master Device
Program processing Hardware operation Program processing
SCK pin
12
345
6
78
9
1
2
SB0 or SB1 pin
BUSY
READY
D7
Hardware operation
D6
D5
D4
D3
D2
D1
D0
ACK
BUSY
D7
D6
READY
Data
Master device processing (receiver) Transfer line Slave device processing (transmitter)
Write FFH to SIO
Read SIO
Set ACKT
Receive data processing
Stop SCK
Serial reception
Generate IRQCSI
Output ACK
Serial reception
Write to SIO
Write to SIO
Clear BUSY
Serial transmission
Generate IRQCSI
Set ACKD
Output BUSY
Clear BUSY
Write FFH to SIO