
CHAPTER 1 INTRODUCTION
The V850 family is a collection of NEC’s single-chip microcontrollers that have a CPU core using the RISC
microprocessor technology of the V800 Series
TM
, with on-chip ROM/RAM and peripheral I/Os, etc.
The V850 family of microcontrollers provides a migration path to the existing NEC’s original single-chip microcontroller
“78K Series”, and boasts higher cost-performance.
This chapter briefly outlines the V850 family.
1.1 General
Real-time control systems are used in a wide range of applications, including:
office equipment such as HDDs (Hard Disk Drives), PPCs (Plain Paper Copiers), printers, and facsimiles,
automobile electronics such as engine control systems and ABSs (Antilock Braking Systems), and
factory automation equipment such as NC (Numerical Control) machine tools and various controllers.
The great majority of these systems employed 8-bit or 16-bit microcontrollers so far. However,the perform-
ance level of these microcontrollers has become inadequate in recent years as control operations have risen
in complexity, leading to the development of increasingly complicated instruction sets and hardware design.
As a result, the need has arisen for a new generation of microcontrollers operable at much higher frequencies
to achieve an acceptable level of performance under today's more demanding requirements.
The V850 family of microcontrollers was developed to satisfy this need. This family uses RISC architecture
that can provide maximum performance with simpler hardware, allowing users to obtain a performance ap-
proximately 15 times higher than that of the existing 78K/III Series and 78K/IV Series CISC single-chip
microcontrollers at a lower total cost.
In addition to the basic instructions of conventional RISC CPUs, the V850 family is provided with special
instructions such as saturate, bit manipulate, and multiply/divide (executed by a hardware multiplier) instruc-
tions, which are especially suited for digital servo control systems. Moreover, instruction formats are de-
signed for maximum compiler coding efficiency, allowing the reduction of object code sizes.
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