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S3C8248/C8245/P8245/C8247/C8249/P8249
INDEXED ADDRESSING MODE (Concluded)
4-bit Working
Register Address
Sample Instructions:
LDC
LDE
Program Memory
OFFSET
OFFSET
dst/src
src
OPCODE
R4, #1000H[RR2]
R4,#1000H[RR2]
Figure 3-9. Indexed Addressing to Program or Data Memory
MSB Points to
RP0 or RP1
~
NEXT 2 Bits
Point to Working
Register Pair
LSB Selects
+
16-Bits
8-Bits
16-Bits
; The values in the program address (RR2 + 1000H)
are loaded into register R4.
; Identical operation to LDC example, except that
external program memory is accessed.
ADDRESSING MODES
Register File
RP0 or RP1
~
Register
Pair
Program Memory
or
Data Memory
Value used in
OPERAND
Instruction
Selected
RP points
to start of
working
register
block
16-Bit
address
added to
offset
3-9
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