INSTRUCTION SET S3F80P5_UM_ REV1.00
LDW — Load Word
LDW dst,src
Operation: dst ← src
The contents of the source (a word) are loaded into the destination. The contents of the source
are unaffected.
Flags: No flags are affected.
Format:
Bytes Cycles Opcode
(Hex) Addr Mode
dst src
opc src dst 3 8 C4 RR RR
8 C5 RR IR
opc dst src 4 8 C6 RR IML
Examples: Given: R4 = 06H, R5 = 1CH, R6 = 05H, R7 = 02H, register 00H = 1AH,
register 01H = 02H, register 02H = 03H, and register 03H = 0FH:
LDW RR6,RR4 → R6 = 06H, R7 = 1CH, R4 = 06H, R5 = 1CH
LDW 00H,02H → Register 00H = 03H, register 01H = 0FH,
register 02H = 03H, register 03H = 0FH
LDW RR2,@R7 → R2 = 03H, R3 = 0FH,
LDW 04H,@01H → Register 04H = 03H, register 05H = 0FH
LDW RR6,#1234H → R6 = 12H, R7 = 34H
LDW 02H,#0FEDH → Register 02H = 0FH, register 03H = 0EDH
In the second example, please note that the statement "LDW 00H,02H" loads the contents of the
source word 02H, 03H into the destination word 00H, 01H. This leaves the value 03H in general
register 00H and the value 0FH in register 01H.
The other examples show how to use the LDW instruction with various addressing modes and
formats.
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