UPD75237 Datasheet, PDF (95/191 Pages) NEC – 4-BIT SINGLE-CHIP MICROCOMPUTER

µPD75237
Fig. 4-47 ACKD Operations
(a) When ACK signal is output during the 9th clock period of SCK0.
Transfer Start
Directive
SIO0
Transfer Start
SCK0
6
7
8
9
SB0/SB1
D2 D1 D0
ACK
ACKD
(b) When ACK signal is output after the 9th clock of SCK0
SIO0
SCK0
6
7
8
9
SB0/SB1
D2 D1 D0
ACK
ACKD
Transfer Start
Directive
Transfer Start
(c) Clear timing with transfer start command during BUSY
SIO0
Transfer Start Directive
SCK0
SB0/SB1
6
7
8
9
D2 D1 D0
ACK
BUSY
D7 D6
ACKD
SCK0
SB0/SB1
BSYE
Fig. 4-48 BSYE Operation
6
7
8
9
ACK
BUSY
When BSYE=1
at this point
When reset during this pe-
riod and BSYE=0 at the fall-
ing edge of SCK0
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