Zilog
Zilog, Inc. is an American manufacturer of 8-bit and 16-bit microcontrollers. Its most famous product is the Z80 series of 8-bit microprocessors that were compatible with the Intel 8080 but significantly cheaper. The Z80 was widely used during the 1980s in many popular home computers such as the TRS-80, MSX, Amstrad CPC and the ZX Spectrum, as well as arcade games such as Pac-Man. The company also made 16- and 32-bit processors, but these did not see widespread use. From the 1990s, the company focused primarily on the microcontroller market.

The name (pronunciation varies) is an acronym of Z integrated logic, also thought of as "Z for the last word of Integrated Logic".  In the oral history interview video which Federico Faggin (co-founder of Zilog) recorded for the Computer History Museum, he pronounced Zilog with a long "i" consistently.

History
Zilog was started in California in 1974 by Federico Faggin and Ralph Ungermann, who both left Intel after working on the 4004 and 8080 microprocessors and custom chips. Masatoshi Shima, who also worked with Faggin on the 4004 and 8080, joined Zilog in 1975. Ungermann had a falling-out with Faggin and left Zilog in 1978. The company became a subsidiary of Exxon in 1980, but the management and employees bought it back in 1989, led by Dr. Edgar Sack.

Zilog went public in 1991, but was acquired in 1998 by Texas Pacific Group. Curtis Crawford replaced Dr. Sack and changed the company's direction towards 32-bit data communications processors. Bonds were sold against the company to fund the new developments, but after the Internet bubble burst in 2000 and the resultant reduction in customer demand for such products, Curtis Crawford was replaced by James (Jim) Thorburn, who reorganized the company under Chapter 11 bankruptcy in late 2001 and refocused it on the 8- and 16-bit microcontroller market.

Jim Thorburn led Zilog back into profitability, and by FY 2007, Zilog had $82 million in sales. During this time, the company developed the Z8 Encore! 8-bit Flash MCU and ZNEO 16-bit Flash MCU product families. In February 2007, Zilog hired Darin Billerbeck to replace Jim Thorburn as president and CEO.

The last year Zilog introduced any new 8-bit microcontroller products was 2007. With no new product road map, FY2008 sales fell 20% to $67.2 million. Sales fell 46% in FY2009 to $36.2 million.

In January 2008, Zilog declined an unsolicited proposal made by Universal Electronics Inc. to acquire the company.

On February 19, 2009, Zilog announced that it had sold off its 8-bit Crimzon Universal Remote Control infrared microcontroller product line, as well as its ARM9 32-bit microcontrollers, including the Zatara security microcontrollers and 15 patents, to Maxim Integrated Products. Remote control manufacturer Universal Electronics Inc. purchased all of Zilog's software and intellectual property assets related to Zilog's universal remote control business, including all ROM code, software, and database of infrared codes. Zilog sold these assets for $31 million cash.

In December 2009, IXYS Corporation bought the company for $62.4 million in cash, which was significantly below the market valuation of Zilog's stock at the time. Details of the acquisition have been under investigation.

Since early 2010, Zilog has refocused its efforts toward satisfying the industrial and consumer markets for motion detection, motor control, RF wireless and embedded security applications, and is currently producing a number of reference designs that integrate its 8- and 16-bit microcontrollers with IXYS power management products.

In February 2012, Zilog announced the release of its Z8051 family of microcontrollers and tool sets to fill a vacancy in the developer market for 8051 cores that was created when chip-maker NXP Semiconductors exited the 8051 market. Later that year, Zilog announced its ZGATE Embedded Security solution, which incorporates its eZ80F91 MCU and TCP/IP stack with an embedded firewall to offer protection against cyber threats and attacks at the chip level.

In August 2017, Zilog and its parent IXYS Corporation were acquired by Littelfuse Inc in exchange for $750 million in cash and stocks.

Microprocessors

Z80
The Z80(i) is an improved implementation of the Intel 8080 architecture, with substantial extensions to the register model and instruction set and with added hardware interface features.
At introduction, the Z80 was faster, more capable, and much cheaper than the 8080.  Alongside the 6502, the Z80 was one of the most popular 8-bit processors for general purpose microcomputers and other applications from the late 1970s well into the 1980s, and modern CMOS versions of both CPUs are still in production and use today (as of May 2021). The Z80 CPU was used in the Sinclair ZX80, ZX81, ZX Spectrum and the Amstrad CPC home computers as well as the MSX architecture and the Microbee and Tandy TRS-80 (models I, II, III, 4, and others). The CP/M-80 operating system (and its huge software library featuring hits like WordStar and dBase) was known to be the Z80 disk operating system, and its success is partly due to the popularity of the Z80. The 1985 Commodore 128 added a Z80 to the Commodore 64 hardware allowing it to run CP/M software; the DEC Rainbow 100 similarly added a Z80 to an Intel 8088-based MS-DOS computer to enable the machine to run both MS-DOS and CP/M software natively.

The Z80 was a common choice for creators of video games during the Golden age of arcade video games, with a Z80 powering Pac-Man, dual Z80s in Scramble, and three in each Galaga machine.  It was the central processor for the ColecoVision game console (1982) and Sega's Master System (1986) and Game Gear (1990).

In the 1990s, the Z80 was the CPU of the Texas Instruments graphing calculator series, as well as being used as the secondary/support CPU in the Sega Genesis (most typically used for sound).

Other chips
After the Z80 Zilog introduced the 16-bit Z8000 and 32-bit Z80000 processors, but these were not particularly successful, and the company refocused on the microcontroller market, producing both basic CPUs and application-specific integrated circuits/standard products (ASICs/ASSPs) built around a CPU core. As well as producing processors, Zilog has produced several other components. One of the most famous was the Zilog SCC serial communications controller as found on early Apple Macintosh, Sun SPARCstations and SPARCservers up to the SPARCstation 20.

Zilog also formed a Systems Division, which designed the Zilog System 8000, a Z8000- or Z80000-based multiuser computer system running a Unix derivative called ZEUS (Zilog Enhanced UNIX System).

Zilog attempted to enter the 32-bit microcontroller market in February 2006 with the demonstration of ARM9-based Point-Of-Sale (POS) microcontroller product line.  The final product was released in 2007 called Zatara. Sales were disappointing and the entire ARM9 series was sold to Maxim Integrated Products in 2009.

Zilog also produced Zdots single board computers. It includes Zilog eZ80AcclaimPlus controller, 1MB flash memory, 512KB SRAM, 10BaseT Ethernet Controller, IrDA transceiver, 2 x 60-pin system expansion interface with full MPU bus/control signals, RJ-45 Ethernet connector. Motion detection version includes Z8 Encore! XP MCU.

Product list

Microprocessor families
 Zilog Z80 (1976)
 Zilog Z8000 (ca 1978)
 Zilog Z800 (1985)
 Zilog Z80000 (late 1985)
 Zilog Z280 (early 1986)
 Zilog Z180 (late 1986)

Microcontroller families
 Zilog Z380 (1994)
 Zilog Z8 Encore!
 Zilog Z8 Encore! XP
 Zilog eZ80 (2001)
 Zilog eZ8  (2005)
 Zilog Z16F, ZNEO, 16-bit microcontroller  (2006)
 Zilog Z8051  (2011)

Communication controllers
Z8030/Z8530 SCC and Z80230/Z85230 ESCC USART chips
Z16017/Z16M17/Z86017 PCMCIA adapter
Z80382/Z8L382 microprocessor
Z5380 SCSI protocol controller (based on NCR 5380)
Z022 series single-chip modem

Motion detection
ZEPIR0AAS02MODG - ZMOTION™ Motion Detection Module
Z8FS040 ZMOTION™ MCU - Microcontroller with built-in motion detection algorithms
Z8FS021A - ZMOTION™ Intrusion MCU - Microcontroller with built-in intrusion motion detection algorithms

Digital signal processor
Z86295
Z89 series

TV controllers
Z90231
Z90233
Z90251
Z90255

Line 21 decoders
Z86129/Z86130/Z86131
Z86228/Z86229/Z86230

Single board computers
Zdots eZ80F91

See also
 Z80-RIO
 Applied Digital Data Systems
 LaFarr Stuart, Zilog's 4th employee

References

External links
 

Electronics companies established in 1974
Companies that filed for Chapter 11 bankruptcy in 2001
TPG Capital companies
Semiconductor companies of the United States
1974 establishments in California
2009 mergers and acquisitions
Companies based in Milpitas, California