GMS87C4060 Datasheet, PDF (29/102 Pages) Hynix Semiconductor – 8-BIT SINGLE-CHIP MICROCONTROLLERS

PRELIMINARY
GMS81C4040/87C4060
8.4 Addressing Mode
The GMS800 series uses six addressing modes;
• Register addressing
• Immediate addressing
• Direct page addressing
• Absolute addressing
• Indexed addressing
• Register-indirect addressing
(1) Register Addressing
Register addressing accesses the A, X, Y, C and PSW.
(2) Immediate Addressing → #imm
In this mode, second byte (operand) is accessed as a data
immediately.
Example:
FE10: 0435
ADC
#35H
MEMORY
0FE10_H
04
35
A+35H+C → A
When G-flag is 1, then RAM address is defined by 16-bit
address which is composed of 8-bit direct page accessable
register (DPGR) and 8-bit immediate data.
Example: G=1, DPGR=0CH
F100: E45535 LDM
35H,#55H
0C35_H
data
~~
þ
0F100_H
E4
0F101_H
55
0F102_H
35
data ← 55H
~~
A
(3) Direct Page Addressing → dp
In this mode, a address is specified within direct page.
Example; G=0
E551: C535
LDA
35H;A ←RAM[35H]
35_H
data
~~
0E550_H
C5
0E551_H
35
À
~~ _þ data → A
(4) Absolute Addressing → !abs
Absolute addressing sets corresponding memory data to
Data , i.e. second byte(Operand I) of command becomes
lower level address and third byte (Operand II) becomes
upper level address.
With 3 bytes command, it is possible to access to whole
memory area.
ADC, AND, CMP, CMPX, CMPY, EOR, LDA, LDX,
LDY, OR, SBC, STA, STX, STY
Example;
F100: 0735F0 ADC!0F035H ;A ←ROM[0F035H]
0F035_H
data
~~
0F100_H
07
0F101_H
35
0F102_H
F0
A
~~
A+data+C → A
P
address: 0F035
Nov. 1999 Ver 1.0
PRELIMINARY
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