Computer Hardware User's Manual

77
CHAPTER 5 EXPLANATION OF INSTRUCTIONS
User's Manual U12326EJ4V0UM
Rotate Left
ROL
Byte Data Rotation to the Left
[Instruction format] ROL dst, cnt
[Operation] (CY, dst
0 ← dst7, dstm+1 ← dstm) × one time
[Operand]
Mnemonic Operand(dst,cnt)
ROL A, 1
[Flag]
ZACCY
×
[Description]
• The destination operand (dst) contents specified by the 1st operand are rotated to the left just once.
• The MSB (bit 7) contents are simultaneously rotated to LSB (bit 0) and transferred to the CY flag.
[Description example]
ROL A, 1; The A register contents are rotated to the left by one bit.
CY 07