The Ricoh 5A22 is a microprocessor

Microprocessor

A microprocessor incorporates the functions of a computer's central processing unit on a single integrated circuit, or at most a few integrated circuits. It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and...

 produced by Ricoh

Ricoh

or Ricoh, is a Japanese company that was established in 1936 on February 6th, as , a company in the RIKEN zaibatsu. Its headquarters is located in Ricoh Building in Chūō, Tokyo....

 for the Super Nintendo Entertainment System (SNES)

Super Nintendo Entertainment System

The Super Nintendo Entertainment System is a 16-bit video game console that was released by Nintendo in North America, Europe, Australasia , and South America between 1990 and 1993. In Japan and Southeast Asia, the system is called the , or SFC for short...

 video game console. The 5A22 is based around the 16-bit

16-bit

-16-bit architecture:The HP BPC, introduced in 1975, was the world's first 16-bit microprocessor. Prominent 16-bit processors include the PDP-11, Intel 8086, Intel 80286 and the WDC 65C816. The Intel 8088 was program-compatible with the Intel 8086, and was 16-bit in that its registers were 16...

 CMD/GTE 65c816, itself a version of the WDC

Western Design Center

The Western Design Center , located in Mesa, Arizona, USA, is a company developing and manufacturing MOS 65xx-based microprocessors, microcontrollers , and related support chips...

 65C816 (used in the Apple IIGS

Apple IIGS

The Apple , the fifth and most powerful model in the Apple II series of personal computers produced by Apple Computer. The "GS" in the name stands for Graphics and Sound, referring to its enhanced graphics and sound capabilities, both of which greatly surpassed previous models of the line...

 personal computer).

All of the above mentioned processors are based on the MOS Technology 6502

MOS Technology 6502

The MOS Technology 6502 is an 8-bit microprocessor that was designed by Chuck Peddle and Bill Mensch for MOS Technology in 1975. When it was introduced, it was the least expensive full-featured microprocessor on the market by a considerable margin, costing less than one-sixth the price of...

 family of processors.

Major features

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

• Controller port interface circuits, including both serial
  Serial communications
  In telecommunication and computer science, serial communication is the process of sending data one bit at a time, sequentially, over a communication channel or computer bus. This is in contrast to parallel communication, where several bits are sent as a whole, on a link with several parallel channels...
  
   and parallel
  Parallel communications
  In telecommunication and computer science, parallel communication is a method of sending several data signals simultaneously over several parallel channels...
  
   access to controller data
• An 8-bit parallel I/O port, which was mostly unused in the SNES
• Circuitry for generating NMI
  Non-Maskable interrupt
  A non-maskable interrupt is a computer processor interrupt that cannot be ignored by standard interrupt masking techniques in the system. It is typically used to signal attention for non-recoverable hardware errors...
  
   interrupt
  Interrupt
  In computing, an interrupt is an asynchronous signal indicating the need for attention or a synchronous event in software indicating the need for a change in execution....
  
  s on V-blank
  Vertical blanking interval
  The vertical blanking interval , also known as the vertical interval or VBLANK, is the time difference between the last line of one frame or field of a raster display, and the beginning of the first line of the next frame. It is present in analog television, VGA, DVI and other signals. During the...
  
  
• Circuitry for generating IRQ
  Interrupt request
  The computing phrase "interrupt request" is used to refer to either the act of interrupting the bus lines used to signal an interrupt, or the interrupt input lines on a Programmable Interrupt Controller...
  
   interrupt
  Interrupt
  In computing, an interrupt is an asynchronous signal indicating the need for attention or a synchronous event in software indicating the need for a change in execution....
  
  s on calculated screen positions
• A DMA
  Direct memory access
  Direct memory access is a feature of modern computers that allows certain hardware subsystems within the computer to access system memory independently of the central processing unit ....
  
   unit, supporting two primary modes:
  • General DMA, for block transfers at a rate of 2.68MB/s
  • H-blank DMA, for transferring small data sets at the end of each scanline outside of the active display period
• Multiplication
  Multiplication
  Multiplication is the mathematical operation of scaling one number by another. It is one of the four basic operations in elementary arithmetic ....
  
   and division
  Division (mathematics)
  right|thumb|200px|20 \div 4=5In mathematics, especially in elementary arithmetic, division is an arithmetic operation.Specifically, if c times b equals a, written:c \times b = a\,...
  
   registers
• Two separate address bus
  Address bus
  An address bus is a computer bus that is used to specify a physical address. When a processor or DMA-enabled device needs to read or write to a memory location, it specifies that memory location on the address bus...
  
  ses driving the 8-bit data bus: a 24-bit "Bus A" for general access, and an 8-bit "Bus B" mainly for APU and PPU registers
  Memory-mapped I/O
  Memory-mapped I/O and port I/O are two complementary methods of performing input/output between the CPU and peripheral devices in a computer...
  
  

Performance

The CPU as a whole employs a variable-speed system bus

System bus

A system bus is a single computer bus that connects the major components of a computer system. The technique was developed to reduce costs and improve modularity....

, 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 MIPS

Instructions per second

Instructions per second is a measure of a computer's processor speed. Many reported IPS values have represented "peak" execution rates on artificial instruction sequences with few branches, whereas realistic workloads typically lead to significantly lower IPS values...

and has a theoretical peak of 1.79 million 16-bit adds per second.