The NEC µPD7720 is the name of fixed point

Fixed-point arithmetic

In computing, a fixed-point number representation is a real data type for a number that has a fixed number of digits after the radix point...

 digital signal processor

Digital signal processor

A digital signal processor is a specialized microprocessor with an architecture optimized for the fast operational needs of digital signal processing.-Typical characteristics:...

s from NEC

NEC

, a Japanese multinational IT company, has its headquarters in Minato, Tokyo, Japan. NEC, part of the Sumitomo Group, provides information technology and network solutions to business enterprises, communications services providers and government....

 (currently Renesas Electronics

Renesas Electronics

is a Japanese semiconductor manufacturer. It is based in Tokyo and has manufacturing, design and sales operations in around 20 countries. Renesas is one of the world's largest manufacturers of semiconductor systems for mobile phones and automotive applications. It is the world's largest...

). It was introduced in 1980, at which time it was the first commercial DSP in the industry. The NEC µPD7720 runs at 4 MHz frequency with 128-word data RAM, 512-word data ROM, and 512-word program memory, which has VLIW-like instruction format, enabling all of ALU

Arithmetic logic unit

In computing, an arithmetic logic unit is a digital circuit that performs arithmetic and logical operations.The ALU is a fundamental building block of the central processing unit of a computer, and even the simplest microprocessors contain one for purposes such as maintaining timers...

operation, address register increment/decrement operation, and move operation in one cycle.

Variants

The NEC µPD77C25, which succeeded the µPD7720, runs at 8 MHz frequency with 256-word data RAM, 1,024-word data ROM, and 2,048-word program memory.