S3P80C5 Datasheet, PDF (57/263 Pages) Samsung semiconductor – 8-Bit CMOS Microcontrollers

ADDRESSING MODES
INDEXED ADDRESSING MODE (Continued)
S3P80C5/C80C5/C80C8
4 Bit Working
Register Address
MSB Points to
RP0 or RP1
Register File
RP0 or RP1
Program Memory
~
~
OFFSET
dst/src
x
OPCODE
Next 2 Bits
Point to Working
Register Pair
(1 of 4)
Register
Pair
LSB Selects
+
8 Bits ^{16 Bits}
Program Memory
or
Data Memory
Selected
RP Points
to Start of
Working
Register
Block
16-Bit
Address
Added to
Offset
Sample Instructions:
LDC
R4, #04H[RR2]
LDE
R4,#04H[RR2]
16 Bits
OPERAND
Value used In
Instruction
; The values in the program address (RR2 + 04H) are
loaded into register R4.
; Identical operation to LDC example, except that
external program memory is accessed.
NOTE: LDE command is not available, because an external interface is not implemented for
the S3C80C5/C80C8/C80C4.
Figure 3-8. Indexed Addressing to Program or Data Memory with Short Offset
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