The Ricoh 5A22 is an 8/16-bit

microprocessor A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit, or a small number of integrated circuits. The microprocessor contains the arithmetic, logic, and control circ ...

produced by

Ricoh is a Japanese Multinational corporation, multinational imaging and electronics company (law), company. It was founded by the now-defunct commercial division of the Riken, Institute of Physical and Chemical Research (Riken) known as the ''Riken ...

for the Super Nintendo Entertainment System (SNES)

video game console A video game console is an electronic device that outputs a video signal or image to display a video game that can be played with a game controller. These may be home consoles, which are generally placed in a permanent location connected to ...

. It is based on the 8/16-bit WDC

65C816 The W65C816S (also 65C816 or 65816) is an 8/16-bit microprocessor (MPU) developed and sold by the Western Design Center (WDC). Introduced in 1985, the W65C816S is an enhanced version of the WDC 65C02 8-bit MPU, itself a CMOS enhancement of the ve ...

, which was developed between 1982 and 1984 for the

Apple IIGS The Apple IIGS (styled as II), the fifth and most powerful of the Apple II family, is a 16-bit personal computer produced by Apple Computer. While featuring the Macintosh look and feel, and resolution and color similar to the Amiga and Atari ST ...

personal computer. It has 92 instructions, an 8-bit

data bus In computer architecture, a bus (shortened form of the Latin '' omnibus'', and historically also called data highway or databus) is a communication system that transfers data between components inside a computer, or between computers. This e ...

, a

16-bit 16-bit microcomputers are microcomputers that use 16-bit microprocessors. A 16-bit register can store 216 different values. The range of integer values that can be stored in 16 bits depends on the integer representation used. With the two mo ...

accumulator, and a 24-bit

address bus In computer architecture, a bus (shortened form of the Latin '' omnibus'', and historically also called data highway or databus) is a communication system that transfers data between components inside a computer, or between computers. This e ...

. The CPU runs between 1.79 MHz and 3.58 MHz, and uses an extended

MOS Technology 6502 The MOS Technology 6502 (typically pronounced "sixty-five-oh-two" or "six-five-oh-two") William Mensch and the moderator both pronounce the 6502 microprocessor as ''"sixty-five-oh-two"''. is an 8-bit microprocessor that was designed by a small te ...

Instruction set architecture, instruction set.

Major features

In addition to the

CPU core, the 5A22 contains support hardware, including: * Controller port interface circuits, including Serial communications, serial access to controller data * An 8-bit parallel I/O port, which is mostly unused in the SNES * Circuitry for generating non-maskable interrupts on Vertical blanking interval, V-blank * Circuitry for generating interrupts on calculated screen positions * A Direct memory access, DMA unit, supporting two primary modes: ** General DMA, for block transfers at a rate of 2.68 MB/s ** Horizontal blanking interval, H-blank DMA, for transferring small data sets at the end of each scanline outside of the active display period * Multiplication and division (mathematics), division registers * Two separate

ses driving the 8-bit

: a 24-bit "Bus A" for general access, and an 8-bit "Bus B" mainly for APU and PPU Memory-mapped I/O, registers

Performance

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. It works at approximately 1.5 Instructions per second, MIPS, and has a theoretical peak performance of 1.79 million 16-bit operations per second.

References

Super Nintendo Entertainment System Nintendo chips 65xx microprocessors Ricoh products {{microcompu-stub

Major features

Performance

See also

References