S3F84B8_UM_REV 1.00
6 INSTRUCTION SET
6-57
6.3.44 LDW — LOAD WORD
LDW
dst,src
Operation
: dst
src
The contents of source (word) are loaded into the destination. The contents of source remain
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, note that the statement “LDW 00H,02H” loads the contents of 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.
Other examples show how to use the LDW instruction with various addressing modes and
formats.