We've just updated MediaWiki and its underlying software. If anything doesn't look or work quite right, please mention it to us. --RanAS

ROR: Difference between revisions

From SnesLab
Jump to: navigation, search
(linkify accumulator)
(→‎External Links: page number)
Line 62: Line 62:


=== External Links ===
=== External Links ===
* [[Eyes & Lichty]] page on ROR: https://archive.org/details/0893037893ProgrammingThe65816/page/n517
* [[Eyes & Lichty]] page 491, on ROR: https://archive.org/details/0893037893ProgrammingThe65816/page/n517
* [[Labiak]] page on ROR: https://archive.org/details/Programming_the_65816/page/n185
* [[Labiak]] page on ROR: https://archive.org/details/Programming_the_65816/page/n185
* [[MCS6500 Manual]] page on ROR: https://archive.org/details/mos_microcomputers_programming_manual/page/n171
* [[MCS6500 Manual]] page on ROR: https://archive.org/details/mos_microcomputers_programming_manual/page/n171

Revision as of 08:51, 20 November 2023

Basic Info
Addressing Mode Opcode Length Speed
Accumulator 6A 1 byte 2 cycles
Absolute 6E 3 bytes 6 cycles*
Direct Page 66 2 bytes 5 cycles*
absolute indexed by X 7E 3 bytes 7 cycles*
direct page indexed by X 76 2 bytes 6 cycles*
Flags Affected
N V M X D I Z C
. . . . .

ROR (Rotate Right) is a 65x instruction that rotates a value and the carry flag right one bit. The least significant bit is shifted into the carry flag. The carry flag is shifted into the most significant bit. Except in accumulator addressing, ROR takes two extra cycles when the accumulator is 16 bits wide. In direct page addressing modes, ROR takes another extra cycle if the low byte of the direct page register is nonzero.

See Also

External Links