GMS81C1102 Datasheet, PDF (39/89 Pages) Hynix Semiconductor – 8-BIT SINGLE-CHIP MICROCONTROLLERS

GMS81C1102 / GMS81C1202
Y indexed direct page (8 bit offset) → dp+Y
This address value is the second byte (Operand) of com-
mand plus the data of Y-register, which assigns Memory in
Direct page.
This is same with above (2). Use Y register instead of X.
Y indexed absolute → !abs+Y
Sets the value of 16-bit absolute address plus Y-register
data as Memory. This addressing mode can specify mem-
ory in whole area.
Example; Y=55_H
D500FA LDA !0FA00H+Y
3F35 JMP [35H]
35H
36_H
~~
0FC0A_H
~~
0FD00H
0A
FC
NEXT
3F
35
~~ ^{— jump to address 0FC0AH}
~~
–
0F900H
D5
0F901_H
00
0F902_H
FA
~~
0FA55_H
data
–
0FA00H+55H=0FA55H
~~
—
data → A
˜
(6) Indirect Addressing
Direct page indirect → [dp]
Assigns data address to use for accomplishing command
which sets memory data(or pair memory) by Operand.
Also index can be used with Index register X,Y.
JMP, CALL
Example;
X indexed indirect → [dp+X]
Processes memory data as Data, assigned by 16-bit pair
memory which is determined by pair data
[dp+X+1][dp+X] Operand plusX-register data in Direct
page.
ADC, AND, CMP, EOR, LDA, OR, SBC, STA
Example; X=10_H
1625 ADC [25H+X]
35_H
05
36_H
F9
~~
0F905_H
data
~~
0FA00_H
16
25
~~ ^{— 0F905H}
– 25 + X(10) = 35H
~~
˜ A + data + C → A
36
Jan. 2002 ver 2.0