Samsung S3C8275X Computer Hardware User Manual


 
S3C8275X/F8275X/C8278X/F8278X/C8274X/F8274X INSTRUCTION SET
6-57
LDCPI/LDEPI Load Memory with Pre-Increment
LDCPI/
LDEPI dst,src
Operation: rr rr + 1
dst src
These instructions are used for block transfers of data from program or data memory from the
register file. The address of the memory location is specified by a working register pair and is first
incremented. The contents of the source location are loaded into the destination location. The
contents of the source are unaffected.
LDCPI refers to program memory and LDEPI refers to external data memory. The assembler
makes 'Irr' an even number for program memory and an odd number for data memory.
Flags: No flags are affected.
Format:
Bytes Cycles Opcode
(Hex)
Addr Mode
dst
src
opc src | dst 2 14 F3 Irr r
Examples: Given: R0 = 7FH, R6 = 21H, and R7 = 0FFH:
LDCPI @RR6,R0 ; (RR6 RR6 + 1)
; 7FH (contents of R0) is loaded into program memory
; location 2200H (21FFH + 1H)
; R0 = 7FH, R6 = 22H, R7 = 00H
LDEPI @RR6,R0 ; (RR6 RR6 + 1)
; 7FH (contents of R0) is loaded into external data memory
; location 2200H (21FFH + 1H)
; R0 = 7FH, R6 = 22H, R7 = 00H