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S3F84K4
ADDRESSING MODES
INDEXED ADDRESSING MODE (Concluded)
Register File
MSB Points to
RP0 or RP1
RP0 or RP1
Program Memory
~
~
OFFSET
4-bit Working
Register Address
OFFSET
dst/src
src
OPCODE
Selected
RP points
to start of
working
register
block
NEXT 2 Bits
Point to Working
Register Pair
LSB Selects
+
8-Bits
Register
Pair
Program Memory
or
Data Memory
16-Bit
address
added to
offset
16-Bits
16-Bits
OPERAND
Value used in
Instruction
Sample Instructions:
LDC
R4, #1000H[RR2]
LDE
R4,#1000H[RR2]
; 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.
Figure 3-9. Indexed Addressing to Program or Data Memory
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