UPD784020 Datasheet, PDF (76/90 Pages) NEC – 16/8-BIT SINGLE-CHIP MICROCOMPUTER

Serial Operation (CSI)
(1) Three-wire serial I/O mode
tWSKL0
SCK
tWSKH0
tCYSK0
SI
SO
mPD784020, 784021
tDSBSK1
tHSBSK1
Output data
tSSSK0 tHSSK0
Input data
(2) SBI mode
Ý Bus release signal transfer
SCK
SB0
tHSBSK2
tWSBL
tWSBH
tSSBSK
Ý Command signal transfer
SCK
SB0
tHSBSK2
tSSBSK
tWSKL0
tWSKH0
tCYSK0
tDSBSK2
tSSSK0
tHSSK0
tHSBSK1
Input/Output data
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