GMS81C1102 / GMS81C1202
12.4 Addressing Mode
The GMS87C1201 and GMS81C1202 use six addressing
modes.
(3) Direct Page Addressing → dp
In this mode, a address is specified within direct page.
Example;
• Register addressing
C535
LDA
35H
;A ←RAM[35H]
• Immediate addressing
• Direct page addressing
• Absolute addressing
0035H
data
➋
• Indexed addressing
~
~
~
data → A
~
➊
• Register-indirect addressing
Below example is shown for GMS81C1202.
0F850H
0F851H
C5
35
(1) Register Addressing
Register addressing accesses the A, X, Y, C and PSW.
(4) Absolute Addressing → !abs
(2) Immediate Addressing → #imm
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.
In this mode, second byte (operand) is accessed as a data
immediately.
Example:
0435
ADC
#35H
With 3 bytes command, it is possible to access to whole
memory area.
MEMORY
ADC, AND, CMP, CMPX, CMPY, EOR, LDA, LDX,
LDY, OR, SBC, STA, STX, STY
04
35
Example;
A+35H+C → A
0735F0 ADC
!0F035H
;A ←ROM[0F035H]
0F035H
data
➋
E45535 LDM
35H,#55H
~
~
~
~
A+data+C → A
➊
0F900H
0F901H
0F902H
07
35
F0
address: 0F035
data
0035H
data ← 55H
~
~
~
~
➊
➋
0F900H
E4
55
35
0F901H
0F902H
34
Jan. 2002 ver 2.0
HYNIX [ HYNIX SEMICONDUCTOR ]
