UPD75518 NEC, UPD75518 Datasheet - Page 92

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

92
Acknowledge detection flag (R)
Busy enable bit (R/W)
ACKD
BSYE
Examples 1. A command signal is output.
1
2
0
1
The transfer start instruction is executed
The RESET signal is entered.
2. RELD and CMDD are tested to identify the types of received data and the types of processing
Condition for being cleared (ACKD = 0)
accordingly.
By setting WUP = 1, this interrupt routine is processed only when an address match is found.
CMD :
DATA :
ADRS :
1
2
The busy signal is output after the acknowledge signal in phase with the falling edge of SCK0.
Fig. 4-36 Format of Serial Bus Interface Control Register (SBIC) (3/3)
The busy signal is automatically disabled.
Busy signal output is stopped in phase with the falling edge of SCK0 immediately after clear
instruction execution.
SEL
SET1
SEL
SKF
BR
SKT
BR
MB15
CMDT
MB15
RELD
!ADRS
CMDD
!DATA
• • • • • • • • •
• • • • • • • • •
• • • • • • • • •
; or CLR1 MBE
; RELD test
; CMDD test
; Command analysis
; Data processing
; Address decode
The acknowledge signal (ACK) is detected (in phase
with the rising edge of SCK0).
Condition for being set (ACKD = 1)
PD75518(A)