![Ic-photo-Hitachi--HD6473238F10--(H8-323-MCU)](https://upload.wikimedia.org/wikipedia/commons/8/81/Ic-photo-Hitachi--HD6473238F10--%28H8-323-MCU%29.JPG)
H8 is the name of a large family of
8-bit,
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 ...
and
32-bit microcontrollers made by
Renesas Technology
is a Japanese semiconductor manufacturer headquartered in Tokyo, Japan, initially incorporated in 2002 as Renesas Technology, the consolidated entity of the semiconductor units of Hitachi and Mitsubishi excluding their dynamic random-access memo ...
, originating in the early 1990s within
Hitachi Semiconductor. An administrator on the Renesas user community boards commented in 2011 that there are no plans for further development of H8 based products. The family of largely CISC machines is unrelated to the higher-performance
SuperH
SuperH (or SH) is a 32-bit reduced instruction set computing (RISC) instruction set architecture (ISA) developed by Hitachi and currently produced by Renesas. It is implemented by microcontrollers and microprocessors for embedded systems.
At the ...
family of 32-bit RISC-like microcontrollers.
It was supported in the
Linux kernel starting with version 4.2 but support was removed in version 5.19.
Variants
Subfamilies include the 8/16-bit H8/300 and H8/500, the 16/32-bit H8/300H and H8S and the 32-bit H8SX series, each with dozens of different variants, varying by speed, selection of built-in
peripherals such as timers and
serial port
In computing, a serial port is a serial communication interface through which information transfers in or out sequentially one bit at a time. This is in contrast to a parallel port, which communicates multiple bits simultaneously in parallel. ...
s, and amounts of
ROM
Rom, or ROM may refer to:
Biomechanics and medicine
* Risk of mortality, a medical classification to estimate the likelihood of death for a patient
* Rupture of membranes, a term used during pregnancy to describe a rupture of the amniotic sac
* ...
,
flash memory and
RAM
Ram, ram, or RAM may refer to:
Animals
* A male sheep
* Ram cichlid, a freshwater tropical fish
People
* Ram (given name)
* Ram (surname)
* Ram (director) (Ramsubramaniam), an Indian Tamil film director
* RAM (musician) (born 1974), Dutch
* ...
. Built-in ROM and flash memory tends to range from 16
KB to 1024 KB, and RAM from 512
B to 512 KB.
The basic architecture of the H8 is patterned after the
DEC PDP-11 architecture
The PDP-11 architecture is a CISC instruction set architecture (ISA) developed by Digital Equipment Corporation (DEC). It is implemented by central processing units (CPUs) and microprocessors used in PDP-11 minicomputers. It was in wide use during ...
, with eight 16-bit
register
Register or registration may refer to:
Arts entertainment, and media Music
* Register (music), the relative "height" or range of a note, melody, part, instrument, etc.
* ''Register'', a 2017 album by Travis Miller
* Registration (organ), th ...
s (the H8/300H and H8S have an additional bank of eight 16-bit registers), and a variety of
addressing mode
Addressing modes are an aspect of the instruction set architecture in most central processing unit (CPU) designs. The various addressing modes that are defined in a given instruction set architecture define how the machine language instructions i ...
s. Unlike the PDP-11 however, the H8 architecture employs
big-endian
In computing, endianness, also known as byte sex, is the order or sequence of bytes of a word of digital data in computer memory. Endianness is primarily expressed as big-endian (BE) or little-endian (LE). A big-endian system stores the most sig ...
byte ordering.
Both H8/300H and H8S have eight 32-bit registers, each of which can be treated as one 32-bit register, two 16-bit registers, or two 8-bit registers, with the H8S having an internal 32-bit configuration. Several companies provide
compiler
In computing, a compiler is a computer program that translates computer code written in one programming language (the ''source'' language) into another language (the ''target'' language). The name "compiler" is primarily used for programs tha ...
s for the H8 family, and there is a complete
GCC port, including a
simulator
A simulation is the imitation of the operation of a real-world process or system over time. Simulations require the use of models; the model represents the key characteristics or behaviors of the selected system or process, whereas the s ...
. There are also various hardware
emulator
In computing, an emulator is hardware or software that enables one computer system (called the ''host'') to behave like another computer system (called the ''guest''). An emulator typically enables the host system to run software or use pe ...
s available.
The family is continued with the H8SX 32-bit controllers.
Applications
![Samsung NC10 - motherboard - Renesas H8S-2110BV-1271](https://upload.wikimedia.org/wikipedia/commons/6/6c/Samsung_NC10_-_motherboard_-_Renesas_H8S-2110BV-1271.jpg)
H8S may be found in
digital camera
A digital camera is a camera that captures photographs in digital memory. Most cameras produced today are digital, largely replacing those that capture images on photographic film. Digital cameras are now widely incorporated into mobile devices ...
s, the
Cybiko
The Cybiko is a Russian handheld computer introduced in the United States by David Yang's company Cybiko Inc. as a retail test market in New York on April 2000, and rolled out nationwide in May 2000. It is designed for teens, featuring its own tw ...
handheld computers, some
ThinkPad
ThinkPad is a line of business-oriented laptop computers and tablets designed, developed and marketed by Lenovo, and formerly by IBM until 2005, when IBM's PC business was acquired by Lenovo. ThinkPads have a distinct black, boxy design la ...
notebooks,
printer
Printer may refer to:
Technology
* Printer (publishing), a person or a company
* Printer (computing), a hardware device
* Optical printer for motion picture films
People
* Nariman Printer (fl. c. 1940), Indian journalist and activist
* James ...
controllers,
smart cards,
chess computer
Computer chess includes both hardware (dedicated computers) and software capable of playing chess. Computer chess provides opportunities for players to practice even in the absence of human opponents, and also provides opportunities for analysi ...
s, music synthesizers and in various
automotive subsystems. The
LEGO Mindstorms RCX, an advanced robot toy/educational tool, uses the H8/300.
Namco
was a Japanese multinational video game and entertainment company, headquartered in Ōta, Tokyo. It held several international branches, including Namco America in Santa Clara, California, Namco Europe in London, Namco Taiwan in Kaohsiung, ...
employed an H8/3002 as a sound processor for various games it made in the late 1990s, notably those using its
System 12 architecture.
H8/500 was being also used on a Nokia 2110 phone.
In popular culture
H8 is referenced in the
Muse
In ancient Greek religion and mythology, the Muses ( grc, Μοῦσαι, Moûsai, el, Μούσες, Múses) are the inspirational goddesses of literature, science, and the arts. They were considered the source of the knowledge embodied in the ...
song "
Space Dementia".
Muse Wiki
/ref>
References
External links
Renesas Electronics
Online training for Renesas products
A community support forum
{{8bitMCUs
Renesas microcontrollers