Ic-photo-Hitachi--HD6473238F10--(H8-323-MCU)

H8 is the name of a large family of

8-bit In computer architecture, 8-bit integers or other data units are those that are 8 bits wide (1 octet). Also, 8-bit central processing unit (CPU) and arithmetic logic unit (ALU) architectures are those that are based on registers or data bu ...

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 In computer architecture, 32-bit computing refers to computer systems with a processor, memory, and other major system components that operate on data in 32-bit units. Compared to smaller bit widths, 32-bit computers can perform large calculati ...

microcontroller A microcontroller (MCU for ''microcontroller unit'', often also MC, UC, or μC) is a small computer on a single VLSI integrated circuit (IC) chip. A microcontroller contains one or more CPUs (processor cores) along with memory and programmab ...

s made by Renesas Technology, 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 th ...

family of 32-bit RISC-like microcontrollers. It was supported in the

Linux kernel The Linux kernel is a free and open-source, monolithic, modular, multitasking, Unix-like operating system kernel. It was originally authored in 1991 by Linus Torvalds for his i386-based PC, and it was soon adopted as the kernel for the GNU ...

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

peripheral A peripheral or peripheral device is an auxiliary device used to put information into and get information out of a computer. The term ''peripheral device'' refers to all hardware components that are attached to a computer and are controlled by the ...

s 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,

flash memory Flash memory is an electronic non-volatile computer memory storage medium that can be electrically erased and reprogrammed. The two main types of flash memory, NOR flash and NAND flash, are named for the NOR and NAND logic gates. Both use t ...

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), the ...

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 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 s ...

. 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 ...

. 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 peri ...

s available. The family is continued with the H8SX 32-bit controllers.

Applications

Samsung NC10 - motherboard - Renesas H8S-2110BV-1271

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 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 controllers,

smart card A smart card, chip card, or integrated circuit card (ICC or IC card) is a physical electronic authentication device, used to control access to a resource. It is typically a plastic credit card-sized card with an embedded integrated circuit (IC) c ...

s, chess computers, 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 th ...

song " Space Dementia".Muse Wiki
/ref>

References

External links

Renesas Electronics

Online training for Renesas products

A community support forum
{{8bitMCUs Renesas microcontrollers