NEC PD750008 - Manual (Page 190)

170
µPD750008 USER'S MANUAL
Figure 5-68. Command Transfer Operation from Master Device to Slave Device
Program processing Hardware operation Program processing
SCK pin
12
345
6
78
9
SB0 or SB1 pin
C7
Hardware operation
C6
C5
C4
C3
C2
C1
C0
ACK
READY
Command
Master device processing (transmitter) Transfer line Slave device processing (receiver)
Interrupt handling (preparation for next serial transfer)
Serial transmission
Generate IRQCSI
Serial reception
Generate IRQCSI
Output BUSY
Clear BUSY
BUSY
Set CMDT
Write to SIO
Set ACKD
Stop SCK
Read SIO
Analyze command
Set ACKT
Clear BUSY
Set CMDD
Output ACK