User manual

Instruction Set
3-68
RISC 16−Bit CPU
SWPB Swap bytes
Syntax SWPB dst
Operation Bits 15 to 8 <−> bits 7 to 0
Description The destination operand high and low bytes are exchanged as shown in
Figure 3−18.
Status Bits Status bits are not affected.
Mode Bits OSCOFF, CPUOFF, and GIE are not affected.
Figure 3−18. Destination Operand Byte Swap
15 8 7 0
Example
MOV #040BFh,R7 ; 0100000010111111 −> R7
SWPB R7 ; 1011111101000000 in R7
Example The value in R5 is multiplied by 256. The result is stored in R5,R4.
SWPB R5 ;
MOV R5,R4 ;Copy the swapped value to R4
BIC #0FF00h,R5 ;Correct the result
BIC #00FFh,R4 ;Correct the result