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ROL: Difference between revisions

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When the accumulator is 8 bits wide, 9 bits are rotated.
When the accumulator is 8 bits wide, 9 bits are rotated.
When the accumulator is 16 bits wide, 17 bits are rotated.
When the accumulator is 16 bits wide, 17 bits are rotated.
==== Syntax ====
<pre>
ROL A
ROL addr
ROL dp
ROL addr, X
ROL dp, X
</pre>


===== Cycle Penalties =====
===== Cycle Penalties =====

Revision as of 21:39, 6 July 2024

Basic Info
Addressing Mode Opcode Length Speed
Accumulator 2A 1 byte 2 cycles
Absolute 2E 3 bytes 6 cycles*
Direct Page 26 2 bytes 5 cycles*
Absolute Indexed by X 3E 3 bytes 7 cycles*
Direct Page Indexed by X 36 2 bytes 6 cycles*
Flags Affected
N V M X D I Z C
. . . . .

ROL (Rotate Left) is a 65x instruction that rotates a value and the carry flag left one bit. The most significant bit is shifted into the carry flag. The carry flag is shifted into the least significant bit.

When the accumulator is 8 bits wide, 9 bits are rotated. When the accumulator is 16 bits wide, 17 bits are rotated.

Syntax

ROL A
ROL addr
ROL dp
ROL addr, X
ROL dp, X
Cycle Penalties

rol.png

See Also

External Links