Rol4 – NEC 78K/0 Series User Manual
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CHAPTER 5 EXPLANATION OF INSTRUCTIONS
User's Manual U12326EJ4V0UM
Rotate Left Digit
ROL4
Digit Rotation to the Left
[Instruction format]
ROL4 dst
[Operation]
A
3-0
← (dst)
7-4
, (dst)
3-0
← A
3-0
, (dst)
7-4
← (dst)
3-0
[Operand]
Mnemonic
Operand(dst)
ROL4
[HL]
Note
Note Specify an area other than the SFR area as operand [HL].
[Flag]
Z
AC
CY
[Description]
•
The lower 4 bits of the A register and the 2-digit data (4-bit data) of the destination operand (dst) are rotated
to the left.
The higher 4 bits of the A register remain unchanged.
A
(HL)
7
4
3
0
7
4
3
0
Before Execution
0001
0010
0100
1000
After Execution
0001
0100
1000
0010
0
0
3
4
7
dst
3
4
7
A
[Description example]
ROL4 [HL];
Leftward digit rotation is executed with the memory contents specified by the A and HL registers.