HMS87C1808B Datasheet, PDF (37/99 Pages) List of Unclassifed Manufacturers – 8-BIT SINGLE-CHIP MICROCONTROLLERS

The operation within data memory (RAM)
ASL, BIT, DEC, INC, LSR, ROL, ROR
Example; Addressing accesses the address 0035_H.
983500 INC !0035H
;A ←RAM[035H]
0035_H
data
~~
0F100_H
98
0F101_H
35
0F102_H
00
3
~~
2
data+1 → data
1
address: 0035
HMS87C1X04B/08B/16B
X indexed direct page, auto increment→ {X}+
In this mode, a address is specified within direct page by the X
register and the content of X is increased by 1.
LDA, STA
Example; X=35_H
DB
LDA {X}+
35_H
data
~~
DB
2
~~
data → A
1 ^{36H → X}
(5) Indexed Addressing
X indexed direct page (no offset) → {X}
In this mode, a address is specified by the X register.
ADC, AND, CMP, EOR, LDA, OR, SBC, STA, XMA
Example; X=15_H
D4
LDA {X}
;ACC←RAM[X].
15_H
data
~~
0E550_H
D4
2
~~
1
data → A
X indexed direct page (8 bit offset) → dp+X
This address value is the second byte (Operand) of command plus
the data of X-register. And it assigns the memory in Direct page.
ADC, AND, CMP, EOR, LDA, LDY, OR, SBC, STA STY,
XMA, ASL, DEC, INC, LSR, ROL, ROR
Example; X=015_H
C645
LDA 45H+X
5A_H
data
~~
0E550_H
C6
0E551_H
45
~~
1
3
2 ^{data → A}
45H+15H=5AH
SEP. 2004 Ver 1.03
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