View source for Zilog

{{Short description|American manufacturer of  microprocessors}}
{{Infobox company
| name = Zilog, Inc.
| logo = Zilog logo.svg
| type = [[Subsidiary]]
| industry = [[Semiconductors]]
| foundation = {{Start date|1974}}
| founders = {{Unbulleted list
   | [[Federico Faggin]]
   | [[Ralph Ungermann]]
   }}
| location_city = [[Milpitas, California]]
| location_country = United States
| num_employees = 174 (2009)<ref>{{cite web |url=http://yahoo.brand.edgar-online.com/displayfilinginfo.aspx?FilingID=6677734-794-407158&type=sect&TabIndex=2&companyid=26894&ppu=%252fdefault.aspx%253fcompanyid%253d26894%2526amp%253bformtypeId%253d7 |title=Zilog Inc 10-K |date=March 2009 |archive-url=https://web.archive.org/web/20131113132816/http://yahoo.brand.edgar-online.com/displayfilinginfo.aspx?FilingID=6677734-794-407158&type=sect&TabIndex=2&companyid=26894&ppu=%252fdefault.aspx%253fcompanyid%253d26894%2526amp%253bformtypeId%253d7 |archive-date=2013-11-13 |url-status=dead}}</ref>
| parent = [[Littelfuse]]
| homepage = {{URL|zilog.com}}
}}

'''Zilog, Inc''', previously stylized as '''ZiLOG''', is an American manufacturer of [[microprocessor]]s, [[microcontroller]]s, and application-specific embedded [[System on a chip|system-on-chip]] (SoC) products'''.'''

The company was founded in 1974 by [[Federico Faggin]] and [[Ralph Ungermann]], who were soon joined by [[Masatoshi Shima]]. All three had left Intel after working on the [[Intel 4004|4004]] and [[Intel 8080|8080]] microprocessors. The company's most famous product is the [[Zilog Z80|Z80]] microprocessor, which played an important role in the evolution of early computing. [[Backward compatible|Software-compatible]] with the Intel 8080, it offered a compelling alternative due to its lower cost and increased performance, propelling it to widespread adoption in [[video game]] systems and [[home computer]]s during the late 1970s and early 1980s.

The name, pronounced with a long "i" ({{IPAc-en|'|z|aɪ|l|ɒ|g}}), is an acronym of ''Z integrated logic'', also thought of as "Z for the last word of Integrated Logic".

==History==
Zilog was started in [[California]] in 1974 by [[Federico Faggin]] and [[Ralph Ungermann]] with support and encouragement from [[ExxonMobil|Exxon]]'s computing division.<ref name=oral>{{cite web|url=http://archive.computerhistory.org/resources/text/Oral_History/Zilog_Z80/102658073.05.01.pdf|title=ZILOG Oral History Panel on the Founding of the Company and the development of the Z80 Microprocessor}}</ref><ref>{{cite web|url=https://historyofcomputercommunications.info/section/9.6/zilog/|title=9.6 Zilog Ungerman-Bass in Brief|access-date=2022-04-04|archive-date=2021-11-20|archive-url=https://web.archive.org/web/20211120111827/https://historyofcomputercommunications.info/section/9.6/zilog/|url-status=dead}}</ref> Both left [[Intel]] after working on the [[Intel 4004|4004]] and [[Intel 8080|8080]] microprocessors and custom chips. [[Masatoshi Shima]], who also worked with Faggin on the 4004 and 8080, joined Zilog in 1975.<ref>{{Cite web |last=Liebson |first=Steven |date=2019-02-19 |title=In Memoriam: Dr. Bernard Peuto, Architect of Zilog's Z8000 and Z8 |url=https://www.eejournal.com/article/in-memoriam-dr-bernard-peuto-architect-of-zilogs-z8000-and-z8/ |access-date=2022-08-15 |website=EEJournal |language=en-US}}</ref> Ungermann did not want the company to become an Exxon subsidiary and left Zilog in 1978.<ref>{{cite web | url=https://historyofcomputercommunications.info/interviews/ralph-ungermann/ | title=Ralph Ungermann &#124; History of Computer Communications | access-date=2023-03-30 | archive-date=2023-02-04 | archive-url=https://web.archive.org/web/20230204213007/https://historyofcomputercommunications.info/interviews/ralph-ungermann/ | url-status=dead }}</ref>

On January 1, 1979, Zilog released the first issue of their comic book ''Captain Zilog'', which featured the Z8000 computer.<ref>{{Cite book |url=https://www.computerhistory.org/collections/catalog/102646293 |title=Captain Zilog! |date=1979 |publisher=Zilog, Inc. |others=Lou Brooks, Joe Kuber |location=U.S.}}</ref> The Z8000, introduced that year, was the company's first 16-bit microprocessor.<ref>{{Cite web |last=Lot |first=Chris |date=2022-08-21 |title=Clover Computer: A Modern Z8000 CP/M Machine |url=https://hackaday.com/2022/08/21/clover-computer-a-modern-z8000-cp-m-machine/ |access-date=2022-09-01 |website=Hackaday |language=en-US}}</ref>

The company became a subsidiary of Exxon in 1980. Exxon initially acquired 51 percent of the company before buying it outright;<ref>{{cite web | url=https://www.theatlantic.com/technology/archive/2013/05/the-time-exxon-went-into-the-semiconductor-business-and-failed/275993/ | title=The Time Exxon Went into the Semiconductor Business (And Failed) | website=[[The Atlantic]] | date=17 May 2013 }}</ref> however, the management and employees bought it back in 1989, led by [[Edgar Sack]].<ref>{{cite news | url=https://www.nytimes.com/1989/06/15/business/company-news-zilog-team-seeks-company.html | title=COMPANY NEWS; Zilog Team Seeks Company | work=The New York Times | date=15 June 1989 }}</ref>

[[File:Zilog Z80.jpg|thumb|Zilog's iconic 8-bit processor, the Z80. Pictured is one of the first Z80s ever made.]]

Zilog went public in 1991, but was acquired in 1998 by [[TPG Capital|Texas Pacific Group]] for $527 million.<ref>{{Cite news |last= |first= |date=1997-07-22 |title=Zilog Agrees to Be Acquired for $527 Million |language=en-US |work=The New York Times |url=https://www.nytimes.com/1997/07/22/business/zilog-agrees-to-be-acquired-for-527-million.html |access-date=2022-08-15 |issn=0362-4331}}</ref> Curtis Crawford replaced Sack and changed the company's direction towards 32-bit data communications processors.

In 1999, Zilog acquired Production Languages Corporation for an unspecified amount less than $10 million.<ref>{{Cite web |last= |last2= |date=1999-12-14 |title=Zilog acquires software-core developer Production Languages Corp. |url=https://www.eetimes.com/zilog-acquires-software-core-developer-production-languages-corp/ |access-date=2022-08-22 |website=EETimes}}</ref>

Bonds were sold against the company to fund the new developments, but after the [[Dot-com bubble|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, Title 11, United States Code|Chapter 11 bankruptcy]] in late 2001 and refocused it on the 8- and 16-bit microcontroller market.

{{plain image with caption|Zilog early logo.svg|upright=0.75|Earliest logo of Zilog}}
{{plain image with caption|Zilog logo 1991.svg|upright=0.75|Logo of Zilog introduced in the 1990s}}

[[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.{{citation needed|date=April 2018}}

In January 2008, Zilog declined an unsolicited proposal made by Universal Electronics Inc. to acquire the company.<ref>{{cite press release |url=http://investor.zilog.com/phoenix.zhtml?c=107835&p=irol-newsArticle&t=Regular&id=1103434& |date=February 4, 2008 |title=Zilog Board of Directors Declines Universal Electronics Inc.'s Unsolicited Proposal |publisher=Zilog |archive-url=https://archive.today/20120711180411/http://investor.zilog.com/phoenix.zhtml?c=107835&p=irol-newsArticle&t=Regular&id=1103434& |archive-date=11 July 2012 |url-status=dead}}</ref>

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.<ref>{{cite web|url=http://www.microcontroller.com/news/Zilog_Sells_Crimzon_Zatara.asp|title=Zilog Sells Off Two Product Lines (February 19, 2009)}}</ref> 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.<ref>{{cite web|url=https://www.sec.gov/Archives/edgar/data/945699/000095012309068753/0000950123-09-068753.txt|title=SEC filing: IXYS and Zilog merger}}</ref><ref>{{cite web|url=http://www.microcontroller.com/news/Zilog_IXYS.asp|title=Zilog Acquired by IXYS}}</ref> Details of the acquisition have been under investigation.

[[File:Zilog Z-80 Microprocessor ad May 1976.jpg|thumb|upright=1.5|A May 1976 advertisement for the Zilog Z-80 8-bit microprocessor]]Since early 2010, Zilog has refocused on 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 [[Intel MCS-51|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.<ref>{{cite web | title=IXYS Corp. agrees to be bought by Littelfuse Inc. in $750 million cash and stock deal | website=Silicon Valley Business Journal | date=August 28, 2017 | url=https://www.bizjournals.com/sanjose/news/2017/08/28/ixys-littelfuse-acquisition.html | access-date=January 10, 2018}}</ref><ref>{{Cite news|url=https://www.electronicsweekly.com/news/business/508082-2017-08/|title=Littelfuse buys Ixys for $750m|date=2017-08-29|work=Electronics Weekly|access-date=2017-09-19|language=en-GB}}</ref>

==Microprocessors==
===Z80===
The Z80(i) is an improved implementation of the [[Intel 8080]] architecture, with substantial extensions to the register model and [[Z80 instruction set|instruction set]] and with added hardware interface features.
At introduction, the Z80 was faster, more capable, and much cheaper than the 8080.  Alongside the [[MOS Technology 6502|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 while modern CMOS versions of the 6502 are still in production and use today, the Z80 was discontinued in 2024.<ref>{{cite web|access-date=2024-05-29 |date=2024-04-30 |title=The End of an Era: Zilog Discontinues the Z80 Microprocessor |publisher=allaboutcircuits.com |url=https://www.allaboutcircuits.com/news/end-of-era-zilog-discontinues-z80-microprocessor/}}</ref> The Z80 CPU was used in the [[Sinclair Research Ltd|Sinclair]] [[ZX80]], [[ZX81]], [[ZX Spectrum]] and the [[Amstrad CPC]] [[home computer]]s as well as the [[MSX]] architecture and the [[Microbee]] and [[Tandy Corporation|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 [[Digital Equipment Corporation]] [[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]]'',<ref>{{KLOV game|id=10816}}</ref> dual Z80s in ''[[Scramble (video game)|Scramble]]'',<ref>{{KLOV game|id=9447}}</ref> and three in each ''[[Galaga]]'' machine.<ref>{{KLOV game|id=7881}}</ref>  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<ref>The Z80 in the Genesis has access to its own dedicated 8 KB of RAM, the sound hardware, the controller ports, the video chip (VDP) (which contains the PSG sound generator), the cartridge slot, the expansion interface, and other Genesis hardware registers, so this Z80 is versatile, even to the point that it can be used for general computation.  The Master System emulation mode of the Genesis uses the Z80 to run the game software while the MC68000 CPU is effectively stopped; this is how Master System games run on the Genesis through the Power Base Converter, which has barely any electronics and is almost a purely passive wiring adapter.  In principle, software on a Genesis cartridge (or on [[Sega CD]] media) could use the Z80 as the main CPU and let the 68000 serve as a support CPU: the functionality of the Z80 in the Genesis is really that general and flexible.  (technical information source: Sega Genesis Programming Manual)</ref>).

===Other chips===
After the Z80 Zilog introduced the [[16-bit computing|16-bit]] [[Z8000]] and [[32-bit computing|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 circuit|application-specific integrated circuits/standard product]]s (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 [[Mac (computer)|Macintosh]], [[Sun Microsystems|Sun]] [[SPARCstation]]s 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).<ref>{{cite web |url=http://www.old-computers.com/history/detail.asp?n=52&t=3 |title=ZILOG Z8000|work=old-computers.com|access-date=2008-04-22|archive-url=https://web.archive.org/web/20230626062517/http://www.old-computers.com/history/detail.asp?n=52&t=3|archive-date=2023-06-26|url-status=dead}}</ref><ref name="fiedler198310">{{cite news | url=https://archive.org/stream/byte-magazine-1983-10/1983_10_BYTE_08-10_UNIX#page/n133/mode/2up | title=The Unix Tutorial / Part 3: Unix in the Microcomputer Marketplace | work=BYTE | date=October 1983 | access-date=30 January 2015 | last=Fiedler |first=Ryan | pages=132}}</ref>

Zilog attempted to enter the 32-bit microcontroller market in February 2006 with the demonstration of [[ARM9]]-based Point-Of-Sale ([[Point of sale|POS]]) microcontroller product line.<ref>{{cite press release |url=http://investor.zilog.com/phoenix.zhtml?c=107835&p=irol-newsArticle&t=Regular&id=812418& |title=ZiLOG(R) Unveils 32-Bit ARM-9(R) Application-Specific Strategy to Focus on Security and Point-of-Sale Markets |publisher=Zilog |archive-url=https://archive.today/20120710053911/http://investor.zilog.com/phoenix.zhtml?c=107835&p=irol-newsArticle&t=Regular&id=812418& |archive-date=2012-07-10 |url-status=dead}}</ref><ref>{{cite web |url=http://www.microcontroller.com/news/zilog_arm.asp |title=New ZiLOG ARM9 Microcontroller Product Line}}</ref>  The final product was released in 2007 called Zatara.<ref>{{cite press release |url=http://investor.zilog.com/phoenix.zhtml?c=107835&p=irol-newsArticle&t=Regular&id=1053622& |title=Zilog Leads the Secure Transactions Market with New 32-bit High Security Zatara(TM) Series ARM(R) Core Based ASSP |publisher=Zilog |archive-url=https://archive.today/20120710053128/http://investor.zilog.com/phoenix.zhtml?c=107835&p=irol-newsArticle&t=Regular&id=1053622& |archive-date=2012-07-10 |url-status=dead}}</ref> 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.<ref>{{Cite web |url=http://www.embeddedstar.com/weblog/2008/07/15/ez80f917050sbcg/ |title=Zilog Zdots eZ80F91 Module |access-date=2009-03-28 |archive-date=2016-05-07 |archive-url=https://web.archive.org/web/20160507040021/http://www.embeddedstar.com/weblog/2008/07/15/ez80f917050sbcg/ |url-status=dead }}</ref> Motion detection version includes Z8 Encore! XP MCU.<ref>{{cite web |url=http://www2.electronicproducts.com/Zilog_ePIR_Enhanced_Motion_Detection_ZDOTS_Single_Board_Computer_Bolsters_Energy_Management_For_Vending_And_Ot-article-news_07_30_oct2008-html.aspx |title=Zilog ePIR Enhanced Motion Detection ZDOTS Single Board Computer Bolsters Energy Management For Vending And Other Applications Back}}</ref>

==Product list==
===Microprocessor families===
* [[Zilog Z80]] (1976)
* [[Zilog Z8000]] (1979)
* [[Zilog Z800]] (1985)
* [[Zilog Z80000]] (late 1985)
* [[Zilog Z280]] (early 1986)
* [[Zilog Z180]] (late 1986)
* [[Zilog eZ80]] (2001)

===Microcontroller families===
* [[Zilog Z380]] (1994)
* [[Zilog Z8]] (1979)
** Zilog [[Z8 Encore!]]
** Zilog [[Z8 Encore!|Z8 Encore! XP]]
* [[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 Corporation|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

===Microcomputers===
* MCZ 1 series<ref>{{cite web |title=Zilog Z-80 Microcomputer System |url=https://www.computinghistory.org.uk/det/12157/Zilog-Z-80-Microcomputer-System/ |website=Centre for Computing History |access-date=5 May 2023}}</ref><ref>{{cite web |title=Zilog MCZ-1 Series Microcomputer System |year=1977 |url=https://archive.org/details/mcz1seriesmicrocomputersystem/ |access-date=5 May 2023}}</ref>
* MCZ 2 series
* ZDS series<ref>{{cite web |title=Zilog MCZ 1/20 Z80 system |url=http://www.retrotechnology.com/restore/zilog.html |website=retrotechnology.com |access-date=5 May 2023}}</ref>

===Local area networking===
*Z-Net - local networking architecture<ref>{{cite web |title=Your gateway to the future |url=https://www.thenimbus.co.uk/downloads/Zilog-Z-Net.pdf |website=RM Nimbus Museum |publisher=Zilog |access-date=5 May 2023}}</ref>

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

==References==
{{Reflist|30em}}

==External links==
* {{Official website|www.zilog.com}}

{{Zilog}}
{{Authority control}}

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