Samsung C8274X Manuel D’Utilisation
ADDRESSING MODES
S3C8275X/F8275X/C8278X/F8278X/C8274X/F8274X
3-8
INDEXED ADDRESSING MODE
(Continued)
Register File
OPERAND
Program Memory
or
Data Memory
Point to Working
Register Pair
(1 of 4)
LSB Selects
16-Bit
address
added to
offset
address
added to
offset
RP0 or RP1
MSB Points to
RP0 or RP1
Selected
RP points
to start of
working
register
block
RP points
to start of
working
register
block
dst/src
OPCODE
Program Memory
x
OFFSET
4-bit Working
Register Address
Sample Instructions:
LDC
R4, #04H[RR2]
; The values in the program address (RR2 + 04H)
are loaded into register R4.
are loaded into register R4.
LDE
R4,#04H[RR2]
; Identical operation to LDC example, except that
external program memory is accessed.
external program memory is accessed.
NEXT 2 Bits
Register
Pair
Value used in
Instruction
Instruction
8-Bits
16-Bits
16-Bits
+
~
~
Figure 3-8. Indexed Addressing to Program or Data Memory with Short Offset