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CPU6502 Instruction Manual v2.1
Sunplus reserves the rights to change this documentation without prior notice.
09/13/2005
18
Indexed indirect addressing mode
The pre-indexed indirect addressing mode uses “ (adr 08 and X)” to specify a memory address.
Only register X can be used in this mode. The pre-indexed indirect address is a zero-page
indexed direct address. Thus, the valid address must be on page zero.
Operation :
OP-Code
(Adr 08, X)
Example:
AND
($20, X)
N V D I Z C
! - - - ! -
xx
rr
mm
mm
A
SP
X
PC
yy
pp
Data Memory
ppqq
00rr+20
00rr+21
xx AND yy
+
20
21
mmmm+1
mmmm+2
mmmm+2
1
2
Program Memory