Quizzes Lists Topics
WDC 65C02

The Western Design Center (WDC) 65C02 microprocessor is an enhanced CMOS version of the popular NMOS-based 8-bit MOS Technology 6502 microprocessor—the CMOS redesign being made by Bill Mensch in 1978. Over various periods of time, the 65C02 has been second-sourced by NCR, GTE, Rockwell, Synertek and Sanyo. The 65C02 has been used in some home computers, as well as in embedded applications, including medical-grade implanted devices.

W65C02S microprocessor in a PDIP-40 package.

Introduction and features

The 65C02 is a low cost, general-purpose 8-bit microprocessor (8-bit registers and data bus) with a 16-bit program counter and address bus. The variable length instruction set and manually optimized core size are intended to make the 65C02 well suited for low power system-on-chip (SoC) designs.

A Verilog hardware description model is available for designing the W65C02S core into an application-specific integrated circuit (ASIC) or a field-programmable gate array (FPGA). As is common in the semiconductor industry, WDC offers a development system, which includes a developer board, an in-circuit emulator (ICE) and a software development system.

The W65C02S–14 is the production version of the 65C02 microprocessor, and is available in PDIP, PLCC and QFP packages through distribution. The maximum officially supported ϕ2 (primary) clock speed is 14 MHz, indicated by the –14 part number suffix. The "S" designation indicates that the part has a fully static core, a feature that allows ϕ2 to be slowed down or fully stopped in either the high or low state with no loss of data. Typical microprocessors not implemented in CMOS have dynamic cores and will lose their internal register contents (and thus crash) if they are not continuously clocked at a rate between some minimum and maximum specified values.

General logic features
Logic features
  • Vector pull (VPB) output indicates when interrupt vectors are being addressed
  • Memory lock (MLB) output indicates to other bus masters when a read-modify-write instruction is being processed
  • WAit-for-Interrupt (WAI) and SToP (STP) instructions reduce power consumption, decrease interrupt latency and enable synchronization with external events
Electrical features
  • Supply voltage specified at 1.71 V to 5.25 V
  • Current consumption (core) of 0.15 and 1.5 mA per MHz at 1.89 V and 5.25 V respectively
  • Variable length instruction set, enabling code size optimization over fixed length instruction set processors, results in power savings
  • Fully static circuitry allows stopping the clock to conserve power
Clocking features

The W65C02S may be operated at any convenient supply voltage (V) between 1.8 and 5 volts (±5%). The data sheet AC characteristics table lists operational characteristics at 5 V at 14 MHz, 3.3 V or 3 V at 8 MHz, 2.5 V at 4 MHz, and 1.8 V at 2 MHz. This information may be an artifact of an earlier data sheet, as a graph indicates that typical devices are capable of operation at higher speeds than suggested by the AC characteristics table, and that reliable operation at 20 MHz should be readily attainable with V at 5 volts, assuming the supporting hardware will allow it.

The W65C02S may also be operated at non-integral clock rates such as 13.5 MHz (digital SDTV luma sampling rate), 14.31818 MHz (NTSC colour carrier frequency × 4), 14.75 MHz (PAL square pixels), 14.7456 (baud rate crystal), etc., as long as V is sufficient to support the frequency. Designer Bill Mensch has pointed out that F is affected by off-chip factors, such as the capacitive load on the microprocessor's pins. Minimizing load by using short signal tracks and fewest devices helps raise F. The PLCC and QFP packages have less pin-to-pin capacitance than the PDIP package, and are more economical in the use of printed circuit board space.

WDC has reported that FPGA realizations of the W65C02S have been successfully operated at 200 MHz.

Comparison with the NMOS 6502
Instruction set

The 65C02 shares its predecessor's 8-bit instruction set architecture and 16-bit memory address space $0000 to $FFFF allowing access to a total memory map of 64K. "Zero Page" spans $0000 to $00FF. "Page 1" spans memory address space $0100 to $01FF and is dedicated for the stack. On this processor the stack grows downwards with the stack pointer starting at $01FF and decrementing as the stack grows.

The 65C02 adds a number of improvements and documented opcodes, the most useful being instructions that can push or pull the X and Y index registers to/from the stack. Undefined opcodes have been converted into NOPs, although of varying instruction lengths.

Significantly, the defective "indirect jump page wrap" instruction (JMP (), where straddles a memory page boundary) has been fixed, eliminating a source of trouble for unwary assembly language programmers. This instruction has also been enhanced with .X register indexing, making it possible to code JMP (,X), enabling the development of a simple jump table management methodology.

Some variants of the 65C02 (including the WDC W65C02S and the Rockwell R65C00 family) feature individual bit manipulation operations (RMB, SMB, BBR and BBS). The 65SC02 was also available, which lacked these operations.

Status register

Other problems with the 6502, fixed in the 65C02, relate to its program status register, which contains eight system flags. Some flags are set or reset under program control. Others reflect the status of the machine after arithmetic or bit manipulation instructions.

6502 status flags, with meanings when set:

N Negative result
V Sign bit overflow
1 Undefined (always set)
B Break flag (set by BRK instruction)
D Decimal mode enabled
I IRQ disabled
Z Zero result
C Arithmetic carry (borrow)

In all NMOS logic forms of the 6502, the decimal flag (D flag) is not initialized to a known state following reset (state is "random") or when an interrupt is processed (state has been kept from "before the interrupt occurred"), which may lead to arbitrary behavior. This forces 6502 programmers to use the CLD instruction early in the reset handler code (it is generally the second instruction executed after SEI), as well as in the front end of the interrupt handler. The 65C02 addresses these problems by causing the D flag to be cleared at reset or upon receipt of an interrupt (after the status register is pushed onto the stack).

Also, in NMOS 6502s, the N flag is invalid when the processor is operating in decimal mode. The 65C02 fixes this problem (at the cost of an additional clock cycle), and thus increases the usefulness of decimal mode.


The 65SC02 is a variant of the WDC 65C02 without bit instructions.[1]

Notable uses of the 65C02
Home computers
Video game consoles
Other products
See also
  1. Rodnay Zaks, Programmierung des 6502. Jetzt auch mit 6510, 65C02, 65SC02, p. 348
External links
Continue Reading...
Content from Wikipedia Licensed under CC-BY-SA.

The Bill (series 14)


The 14th series of The Bill , a British television drama , consisted of 121 episodes. Background In 1998, with the appointment of new executive producer Richard Handford , discussions were made with broadcaster ITV to return to the format of hour-long episodes, which the show last used on a regular basis in 1987. As such, beginning in August 1998, the show returned to a twice-weekly hour-long format, which it retained for many years until the decision to move the show to a later time-slot came in 2009. It is notable that the first few episodes broadcast in the hour-long format were originally written for the half hour time-slot, and thus, some episodes contain two completely different stories, written by different writers, which jump from one to another. For example, the opening episode, "Deep End", was initially written in three twenty-five minute parts, with a fourth epilogue episode, the first half of "The Party's Over", all conceived by Elizabeth Anne-Wheal. A separate story by Neil Clarke, initially envi

Graham Hill


Norman Graham Hill OBE (15 February 1929 – 29 November 1975) was a British racing driver and team owner from England , who was twice Formula One World Champion. He is the only driver ever to win the Triple Crown of Motorsport —the 24 Hours of Le Mans , Indianapolis 500 and either the Monaco Grand Prix or the Formula One World Drivers' Championship. He also appeared on TV in the 1970s on a variety of non-sporting programmes including panel games. He liked painting in his spare time. Hill and his son Damon were the first father and son pair to have both won the Formula One World Championship. Hill's grandson Josh , Damon's son, also raced his way through the ranks until he retired from Formula Three in 2013 at the age of 22. Hill and five members of the Embassy Hill team died when the twin-engine six-seat Piper Aztec aeroplane he was piloting crashed and burned in foggy conditions at night near Arkley golf course in North London in 1975. Early life Born in Hampstead , London , Hill attended Hendon Technical C

56th Air Defense Artillery Regiment


The 56th Air Defense Artillery is a training regiment in the United States Army. History This number has had two lineages started under it. A 1917 unit that served in France during World War I and in the Americas during World War II, and the 506th Artillery (AA) CAC, which was renumbered in December 1940. After the renumbering a separate lineage was again started for the 506th CA in 1943. The 56th Artillery (Coast Artillery Corps) (C.A.C.) was organized on 1 December 1917 from existing Regular Army units and Connecticut National Guard companies from the Harbor Defenses of Long Island Sound . Moved to the Western Front in France March 1918. Armed with 24 155 mm guns purchased from the French and towed by Holt tractors . Served in the 31st Artillery Brigade, including support of III Army Corps and V Army Corps . Returned to the US January 1919, and moved to Camp Jackson , South Carolina. National Guard companies demobilized early 1919 at Fort Schuyler , New York. Reactivated on 2 June 1941 as the 56th Coas

Markku Alén


Markku Allan Alén (born 15 February 1951, in Helsinki ) is a Finnish former rally and race car driver. He drove for Fiat , Lancia , Subaru and Toyota in the World Rally Championship , and held the record for most stage wins (801) in the series, until Sébastien Loeb overtook it at the 2011 Rally Catalunya . Alén's phrase "now maximum attack" became well-known. Alén never won the world championship itself, despite being for a long time the driver with the most wins to his credit. However, he did win the FIA Cup for Drivers in 1978 , the precursor to the World Championship for Drivers established in 1979 . In 1986 , he was the world champion for eleven days, until Peugeot 's appeal went through and the results of Rallye Sanremo , which Alén had won, were annulled. Career Early Alén's interest in motorsport came from his father, who was the 1963 Finnish champion in ice racing . Alén started his rallying career in 1969 driving a Renault 8 Gordini , and finished ninth at the 1000 Lakes Rally at his first attempt. A

Citroën World Rally Team


The Citroën Total Abu Dhabi World Rally Team is the Citroën factory backed entry into the World Rally Championship , run by Citroën Racing. The team Management Yves Matton – team director Xavier Mestelan-Pinon – technical director Partners Total Abu Dhabi Michelin Eurodatacar History 1990–1998 seasons The Citroën ZX Rally raid won the Rally raid Constructors' Championship in 1993, 1994, 1995, 1996, and 1997 with Pierre Lartigue and Ari Vatanen . Citroën also won the Dakar Rally in 1991, 1994, 1995, and 1996. In addition, Citroën won the Pharaons Rally in 1991, the Tunisia rally in 1992 and the Paris-Moscow-Beijing Rally, also in 1992 1998–2000 seasons Citroën Xsara Kit car at the 1998 Rallye Cantabria In 1998, following its withdrawal from Rally raid competition, Citroën Sport began competing in rallying with the Xsara Kit Car. Equipped with a 2L engine developing 280 hp more than 8 000 rpm, this car started competing in the French Rally Championship in 1998. At the wheel, Philippe Bugalski won drivers titles

Ford World Rally Team


The Ford World Rally Team , also known as the Ford Motor Co. Team prior to 2005, is Ford Motor Company 's full factory World Rally Championship team. In its current form, it has been a competitor since the 1997 season , when Ford Motor Company 's motorsport arm selected the Malcolm Wilson Motorsport company to run its factory team, entering the Ford Escort World Rally Car . The new team took their first victory in the 1997 Acropolis Rally . The team The late Ford Motorsport manager Peter Ashcroft in 1982 Ford team director Malcolm Wilson at the 2011 Rally Finland Management Gerard Quinn senior manager motorsport Ford of Europe Malcolm Wilson team director Christian Loriaux technical director Partners BP Castrol Michelin Icepeak Teng Tools Trade partners Sparco OZ Racing Recaro M-Sport Reiger Racing History 1978 season Ford would end the 1978 season with a win for Hannu Mikkola on season ending Lombard RAC Rally, at the hands of an Escort RS1800, he would be followed home by Björn Waldegård and Britain's Ru

Philippe Alliot


Philippe Alliot (born 27 July 1954 in Voves , Eure-et-Loir , France ) is a former racing driver who participated in Formula One from 1984 to 1990 and from 1993 to 1994 . He raced for RAM , Ligier , Larrousse and McLaren . Early career Prior to his career in Formula One he competed during 1976 and 1977 in Formule Renault , and won the championship in 1978, in the BP Racing team. With said team he also won the French Formula Renault championship and went on to French Formula Three . He finished third in his first race and moved to the European Formula 3 Championship in 1980. By 1983 he moved to Formula Two but hit the headlines that year when he finished third in the Le Mans 24 Hours with Michael and Mario Andretti in a Kremer Porsche . Formula One Alliot driving the Ligier JS33B at the 1990 United States Grand Prix . In 1984 Alliot joined the Skoal Bandit RAM F1 team, but did not enjoy much in the way of success. After Jacques Laffite was injured at the 1986 British Grand Prix , Alliot took his place at Ligier



TiVo's logo , a smiling television set TiVo ( TEE -voh ) is a digital video recorder (DVR) developed and marketed by TiVo Corporation and introduced in 1999. TiVo provides an on-screen guide of scheduled broadcast programming television programs , whose features include "Season Pass" schedules which record every new episode of a series, and "WishList" searches which allow the user to find and record shows that match their interests by title, actor, director, category, or keyword. TiVo also provides a range of features when the TiVo DVR is connected to a home network, including film and television show downloads, advanced search, personal photo viewing, music offerings, and online scheduling. Since its launch in the United States, TiVo has been made available in Australia, Canada, Mexico, New Zealand, Puerto Rico , Sweden, Taiwan , Spain, and the United Kingdom. Newer models, however, have adopted the CableCARD standard, which is only deployed in the United States, and which limits the availability of certain

M-Sport World Rally Team


The M-Sport World Rally Team , formerly Qatar M-Sport World Rally Team , M-Sport Ford World Rally Team and Stobart M-Sport Ford Rally Team , is the privately run World Rally Championship team of M-Sport , the firm run by Malcolm Wilson that was previously responsible for the operation of the former Ford World Rally Team . History 2006 season Wilson at the 2006 Cyprus Rally . Note that the car is named Elaine Joanne, following sponsor Stobart Group's tradition of giving its lorries female names. Stobart debuted at the 2006 season opener Monte Carlo Rally with drivers Matthew Wilson and Pieter Tsjoen. Wilson went on to compete all the 16 rounds for the team. Other Stobart entrants during the season were Luís Pérez Companc in eight rallies, Kosti Katajamäki in five, Jari-Matti Latvala in four, Juan Pablo Raies at the Cyprus Rally and Andreas Mikkelsen at the Wales Rally GB . The team's best results were Latvala's fourth place at the Wales Rally GB and Katajamäki's fifth at the Rally of Turkey and sixth at the Sw

Max Papis


Massimiliano " Max " Papis (born October 3, 1969) is an Italian professional stock car racing driver who has competed in several top-level motorsports events such as Le Mans 24 Hours , Formula One and Champ Car . He has three Champ Car victories. He is the son-in-law of Emerson Fittipaldi . His sons' godfather is fellow Italian Alex Zanardi . Papis also currently drives in the NASCAR Whelen Euroseries . Personal life Papis was born on October 3, 1969 in Como, Italy . He was raised in Italy and got an interest in car racing at a young age, winning several go-kart races and several rounds for racing clubs in Italy. He is married to Tatiana Papis, daughter of the racing driver Emerson Fittipaldi , and has two children, Marco and Matteo Papis. Formula One Papis made his Formula One debut for Footwork at the 1995 British Grand Prix . After a spell as the Lotus team's test driver in 1994 , Papis replaced Gianni Morbidelli in the Footwork team for seven races in the middle of the 1995 Formula One season , as he bro

Whale conservation


Whale conservation is the international environmental and ethical debate over whale hunting . The conservation and anti-whaling debate has focused on issues of sustainability as well as ownership and national sovereignty . Also raised in conservation efforts is the question of cetacean intelligence , the level of suffering which the animals undergo when caught and killed, and the importance that the mammals play in the ecosystem and a healthy marine environment . The International Whaling Commission (IWC) 1986 moratorium on commercial whaling, the value of lethal sampling of whales for scientific research in order to establish catch quotas has also been debated. The value of whaling to fisheries as a method of controlling whales' perceived negative impact on fish stocks is another point of debate. Conservation status Blue whale populations have declined dramatically due to unregulated commercial whaling, putting them at risk of extinction. Prior to the setting up of the IWC in 1946, unregulated whaling had de

BDO World Darts Championship


The BDO World Darts Championship is a world championship competition in darts , organised by the British Darts Organisation (BDO). It began in 1978 , and was, alongside the World Darts Federation 's World Cup of Darts , one of two world championship tournaments until 1993. Since 1994, following a dispute with the BDO and the subsequent fallout, a breakaway group (originally known as the World Darts Council, and now known as the Professional Darts Corporation ) stages its own annual PDC World Championship , generally before the BDO version in late December and early January of each year. The BDO version was first held at the Heart of the Midlands Nightclub in the English city of Nottingham . The following year it moved to the Jollees Cabaret Club, Stoke , where it stayed until 1985. From 1986, it has been held at the Lakeside Country Club in Frimley Green , Surrey . Highlights In 1983 , a 23-year-old qualifier from Ipswich , Keith Deller , beat the world's top 3 players including Eric Bristow in a memorable fi

2014–15 North West Counties Football League


The 2014–15 North West Counties Football League season was the 33rd in the history of the North West Counties Football League , a football competition in England . Teams were divided into two divisions; Premier Division and Division One. Premier Division The Premier Division featured two new teams: Nelson promoted as champions of Division One 1874 Northwich promoted after finishing third in Division One League table Pos Team Pld W D L GF GA GD Pts Qualification or relegation 1 Glossop North End   (C)   (P) 40 33 3 4 100 23 +77 102 Promotion to NPL Division One North 2 Runcorn Linnets 40 28 8 4 89 39 +50 92 3 1874 Northwich 40 26 8 6 90 35 +55 86 4 Colne 40 25 5 10 86 47 +39 80 5 Ashton Athletic 40 21 12 7 69 38 +31 75 6 Squires Gate 40 17 16 7 62 42 +20 67 7 Bootle 40 19 6 15 76 63 +13 63 8 Congleton Town 40 17 9 14 68 57 +11 60 9 A.F.C. Liverpool 40 17 8 15 74 56 +18 59 10 Silsden 40 16 8 16 55 62 −7 56 11 Nelson 40 16 7 17 69 64 +5 55 12 Winsford United 40 15 10 15 66 62 +4 55 13 Runcorn Town 40 13 8 19 72

Javascript Version
Revolvy Server https://www.revolvy.com