Ricoh 5A22

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The Ricoh 5A22 is a microprocessor produced by Ricoh for the Super Nintendo Entertainment System (SNES) video game console. The 5A22 is based on the 8/16-bit CMD/GTE 65c816, itself a version of the WDC 65C816 (used in the Apple IIGS personal computer). It has an 8-bit data bus, a 16-bit accumulator, a 24-bit address bus, and is based on the MOS Technology 6502 family of processors.

Major features[edit]

Ricoh 5A22

In addition to the 65C816 CPU core, the 5A22 contains support hardware, including:


The CPU as a whole employs a variable-speed system bus, with bus access times determined by the memory location accessed. The bus runs at 3.58 MHz for non-access cycles and when accessing Bus B and most internal registers, and either 2.68 or 3.58 MHz when accessing Bus A. It runs at 1.79 MHz only when accessing the controller port serial-access registers.[1] It works at approximately 1.5 MIPS, and has a theoretical peak performance of 1.79 million 16-bit operations per second.

See also[edit]


  1. ^ anomie (December 21, 2008). "Anomie's SNES Memory Mapping Doc" (text). Retrieved June 19, 2019.