W921E400A Datasheet, PDF (44/53 Pages) Winbond – 4-BIT MICROCONTROLLER

W921E400A/W921C400
ROM CODE
b9 b8 b7 b6 b5 b4 b3 b2 b1 b0
decoder code
I3 to I0
b3 b2 b1 b0
B register
b3 b2 b1 b0
A register
ROM ADDRESS
(0 to 4K)
b11 b10 b9 b8 b7 b6 b5 b4 b3 b2 b1 b0
ROM CODE b9 b8 b7 b6 b5 b4 b3 b2 b1 b0
Example:
X Y b3 b2 b1 b0 b3 b2 b1 b0
OP2
OP1
ROM Code Output to Register or Port
XY
OP2
0 0 Disable
0 1 B register
1 0 Port P2
1 1 Both
OP1
Disable
A register
Disable
A register
.
.
.
MOV A, #03H
MOV B, #01H
TBL 02H
.
.
.
ORG 213H
DC
3DCH
.
.
.
;A = 0CH, B = Port2 = 0DH
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