714:
1214:. This style of access makes accessing branch tables simpler as a single base address is used in conjunction with an 8-bit offset. The same could be achieved in the NMOS version using indexed indirect mode, but only if the table was in the zero page, a limited resource. Allowing these to be constructed outside zero page not only lessened the demand for this resource, but also allowed the tables to be constructed in ROM.
1071:
by performing a dummy read of the instruction opcode when indexing crosses a page boundary. However, this fix introduced a new bug that occurs when the base address is on an even page boundary (which means indexing will never cross into the next page). With the new bug, a dummy read is performed on the base address prior to indexing, such that
342:, a feature that allows Ø2 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.
1509:
Rockwell's changes added more bit manipulation instructions for directly setting and testing any bit, and combining the test, clear and branch into a single opcode. The new instructions were available from the start in
Rockwell's R65C00 family, but was not part of the original 65C02 specification and
1549:
RMB and SMB are used to clear (RMB) or set (SMB) individual bits in a bit field, each replacing a sequence of three instructions. As RMB and SMB are zero page addressing only, these instructions are limited in usefulness and are primarily of value in systems in which device registers are present in
1375:
Both WDC and
Rockwell contributed improvements to the bit testing and manipulation functions in the 65C02. WDC added new addressing modes to the BIT instruction that was present in the 6502, as well two new instructions for convenient manipulation of bit fields, a common activity in device drivers.
1070:
When performing indexed addressing, if indexing crosses a page boundary all NMOS variants will read from an invalid address before accessing the correct address. As with a R-M-W instruction, this behavior can cause problems when accessing hardware registers via indexing. The 65C02 fixed this problem
1039:
arithmetic, the NMOS 6502 will update the (N)egative, o(V)erflow and (Z)ero flags to reflect the result of underlying binary arithmetic, that is, the flags are reflecting a result computed prior to the processor performing decimal correction. In contrast, the 65C02 sets these flags according to the
836:
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
898:
On the 6502, some of these leftover codes actually perform computation. Due to the way the 6502's instruction decoder works, simply setting certain bits in the opcode cause parts of the instruction processing to take place. Some of these opcodes immediately crash the processor, while other perform
881:
Although the 65C02 can mostly be thought of as a low-power 6502, it also fixes several bugs found in the original and adds new instructions, addressing modes and features that can assist the programmer in writing smaller and faster-executing programs. It is estimated that the average 6502 assembly
844:
The W65C02S support for arbitrary clock rates allows it to use a clock that runs at a rate ideal for some other part of the system, 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
283:
The basic architecture of the 65C02 is identical to the original 6502, and can be considered a low-power implementation of that design. At 1 MHz, the most popular speed for the original 6502, the 65C02 requires only 20 mW, while the original uses 450 mW, a reduction of over twenty
1062:
is a hardware register. This may occur if the hardware is watching for changes to the value in the register and then performs an action, in this case, it will perform two actions, one with the original value and then again with the new value. The 65C02 instead performs a double read of
1705:
This had the added advantage of slightly improving performance. In the spinning case, the interrupt might arrive in the middle of one of the loop's instructions, and to allow it to restart after returning from the handler, the processor spends one cycle to save its location. With
1086:
If an NMOS 6502 is fetching a BRK (software interrupt) opcode at the same time a hardware interrupt occurs, the BRK will be ignored as the processor reacts to the hardware interrupt. The 65C02 correctly handles this situation by servicing the interrupt and then executing BRK.
1710:, the processor enters the low-power state in a known location where all instructions are guaranteed to be complete, so when the interrupt arrives it cannot possibly interrupt an instruction and the processor can safely continue without spending a cycle saving state.
1668:, STop the Processor, halted all processing until a hardware reset was issued. This could be used to put a system to "sleep" and then rapidly wake it with a reset. Normally this would require some external system to maintain main memory, and it was not widely used.
1674:
t had a similar effect, entering low-power mode, but this instruction woke the processor up again on the reception of an interrupt. Previously, handling an interrupt generally involved running a loop to check if an interrupt has been received, sometimes known as
155:. It uses less power than the original 6502, fixes several problems, and adds new instructions. The power usage is on the order of 10 to 20 times less than the original 6502 running at the same speed; its reduced power consumption has made it useful in
1032:, as well as early in the reset code. The 65C02 automatically clears this flag after pushing the status register onto the stack in response any interrupt or in response to a hardware reset, thus placing the processor back into binary arithmetic mode.
190:. Rockwell's primary interest was in the embedded market and asked for several new commands to be added to aid in this role. These were later copied back into the baseline version, at which point WDC added two new commands of their own to create the
1205:
The 65C02 added the new "indexed absolute indirect" mode which eased the use of branch tables. This mode added the value of the X register to the absolute address and took the 16-bit address from the resulting location. For instance, to access the
42:
1126:
A downside of this model is that if indexing is not needed but the address is in the zero page, one of the index registers must still be set to zero and used in one of these instructions. The 65C02 added a non-indexed indirect addressing mode
1138:
instruction had a unique (among 6502 instructions) addressing mode known as "absolute indirect" that read a 16-bit value from a given memory address and then jumped to the address in that 16-bit value. For instance, if memory location
1103:, adds the X register to the given page zero address before reading the 16-bit vector. In this example, if X is 5, it reads the 16-bit address from location $ 15/$ 16. This is useful when there is an array of pointers in page zero.
894:
of the possible 256 8-bit opcode patterns. The remaining 105 unused opcodes are undefined, with the set of codes with low-order 4-bits with 3, 7, B or F left entirely unused, the code with low-order 2 having only a single opcode.
882:
language program can be made 10 to 15 percent smaller on the 65C02 and see a similar improvement in performance, largely through avoided memory accesses through the use of fewer instructions to accomplish a given task.
1332:, push and pull the X and Y registers to/from the stack. Previously, only the accumulator and status register had push and pull instructions. X and Y could only be stacked by moving them to the accumulator first with
1904:
Wagner's June 1983 article mentions it being available for “several months”. Given typical publication delays at that point this may date it to as early as late 1982. Another source points to 1980, see talk
1458:, which location may be zero page or absolute. The Z flag in the status register is conditioned according to the result of the logical AND—no other status register flags are affected. Furthermore, bits in
1382:
in the 65C02 adds immediate mode, zero page indexed by X and absolute indexed by X addressing. Immediate mode addressing is particularly convenient in that it is completely non-destructive. For example:
1894:
Some sources, including prior versions of this article, claim 1978. This was the date that Bill Mensch, the primary designer, formed WDC. In a 1984 article, Mensch specifically states 1981 as the start
1679:", checking the type when one is received, and then jumping to the processing code. This meant the processor was running during the entire process, even when no interrupts were occurring.
1645:, which has the advantage of allowing it to be replaced by a variable name or calculated number. As is the case with RMB and SMB, BBR and BBS replace a sequence of three instructions.
209:
Early versions used 40-pin DIP packaging, and were available in 1, 2 and 4 MHz versions, matching the speeds of the original nMOS versions. Later versions were produced in
1421:
leaves the value in the accumulator unchanged, so subsequent code can make additional tests against the original value, avoiding having to re-load the value from memory.
857:
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
943:
especially hurt the performance of mantissa normalization in floating-point math routines. The vast majority of machines using the processor support this instruction.
174:
Development of the WDC 65C02 began in 1981 with samples released in early 1983. The 65C02 was officially released sometime shortly after. WDC licensed the design to
260:(X and Y), an 8-bit status register (P), and a 16-bit program counter (PC). In addition to the single accumulator, the first 256 bytes of RAM, the "zero page" (
1510:
not found in versions made by WDC or its other licensees. These were later copied back into the baseline design, and were available in later WDC versions.
837:
operation at higher speeds than suggested by the AC characteristics table, and that reliable operation at 20 MHz should be readily attainable with V
1024:. This means programmers have to set the flag to a known value in order to avoid any bugs related to arithmetic operations. As a result, one finds a
304:
1505:
instruction with additional steps to save the computational changes, but in a way that reports the status of the affected value before it is changed.
1198:. If the driver is updated and the subroutine code moves in memory, any existing code will still work as long as the table of pointers remains at
296:
1362:
version 1 cycle longer (4 cycles). As the address is relative, it is also useful when writing relocatable code, a common task in the era before
1698:
was encountered, processing stopped and the processor went into low-power mode. When the interrupt was received, it immediately processed the
1233:
with no parameters now increment or decrement the accumulator. This was an odd oversight in the original instruction set, which only included
2657:
812:
Variable length instruction set, enabling code size optimization over fixed length instruction set processors, results in power savings
2444:
2502:
902:
The 65C02 adds new opcodes that use some of these previously undocumented instruction slots. For example, $ FF is used for the new
2111:
2714:
2279:
272:
lies in the next 256 bytes, page one ($ 0100 to $ 01FF), and cannot be moved or extended. The stack grows backwards with the
1354:
but uses a 1-byte relative address like other branches, saving a byte. The speed is often the same as the 3 cycle absolute
2709:
2632:
1869:
861:. The PLCC and QFP packages have less pin-to-pin capacitance than the PDIP package, and are more economical in the use of
816:
339:
300:
1016:
More of an oversight than a bug, the state of the (D)ecimal flag in the NMOS 6502's status register is undefined after a
692:
277:
890:
The original 6502 has 56 instructions, which, when combined with different addressing modes, produce a total of 151
269:
1956:
268:), allow faster access through addressing modes that use an 8-bit memory address instead of a 16-bit address. The
1856:
1841:
2400:
1110:
adds the Y register to the 16-bit vector read from the given page zero address. For instance, if Y is 5, and
338:
systems that run faster than the official rating). The "S" designation indicates that the part has a fully
284:
times. The manually optimized core and low power use is intended to make the 65C02 well suited for low power
663:
598:
253:
100:
2245:
1131:
to all instructions that used indexed indirect and indirect indexed modes, freeing up the index registers.
1095:
The 6502 has two indirect addressing modes which dereference through 16-bit addresses stored in page zero:
1363:
1299:
and doesn't require changing the value of the accumulator. As this task is common in most programs, using
187:
179:
931:(rotate left). This was a deliberate design choice by MOS Technology, as it was deemed that implementing
2570:
2495:
2468:
1961:
1830:
1417:
operation changes the value in the accumulator, so the original value loaded from $ 1234 is lost. Using
935:
was too costly in chip area for the benefits it provided. However, clients complained about the missing
868:
WDC has reported that FPGA realizations of the W65C02S have been successfully operated at 200 MHz.
862:
650:
217:
packages, as well as PDIP, and with much higher clock speed ratings. The current version from WDC, the
130:
84:
1222:
In addition to the new addressing modes, the "base model" 65C02 also added a set of new instructions.
303:(FPGA). As is common in the semiconductor industry, WDC offers a development system, which includes a
1036:
593:
2028:
2652:
2608:
2553:
2547:
2542:
2537:
2532:
2526:
2425:
2418:
2320:
2216:
1804:
1756:
308:
203:
152:
121:
2344:
974:, which would then cause the processor to continue execution at the address stored in the vector.
334:
when operated at 5 volts, indicated by the –14 part number suffix (hobbyists have developed 65C02
1816:
1083:. Again, if indexing on hardware register addresses, this bug can result in undefined behavior.
657:
335:
234:
221:
has a fully static core and officially runs at speeds up to 14 MHz when powered at 5 volts.
1570:, which has the advantage of allowing it to be replaced by a variable name or calculated number.
946:
A bug that is present in all NMOS variants of the 6502 involves the jump instruction when using
1985:
713:
2440:
2275:
1058:
and then writing the modified value. This behavior can result in difficult-to-resolve bugs if
1040:
result of decimal arithmetic, at the cost of an extra clock cycle per arithmetic instruction.
1029:
1017:
781:
751:
183:
156:
2449:
2488:
736:
285:
2387:
1501:
is changed. TRB and TSB thus replace a sequence of instructions, essentially combining the
2462:
2076:
2042:
971:
947:
702:
686:
678:
637:
564:
540:
464:
245:
238:
168:
160:
954:
instruction is fetched from memory, the jump vector, rather than being an operand to the
899:
useful functions and were even given unofficial assembler mnemonics by some programmers.
1428:
instruction, WDC added two instructions designed to conveniently manipulate bit fields:
2616:
2517:
2269:
1852:
673:
257:
137:
2703:
1167:
668:
580:
276:(S) starting at $ 01FF and decrementing as the stack grows. It has a variable-length
164:
1607:
The same zero-page addressing and limitations as RMB and SMB apply, but branches to
2688:
2014:
1834:
1676:
1159:
323:
273:
210:
2683:
1190:
is the third entry, zero indexed, and each address requires 16-bits, so to call
982:
850:
802:
643:
249:
199:
2474:
1619:
component of the instruction is often written as part of the mnemonic, such as
1554:
component of the instruction is often written as part of the mnemonic, such as
330:
packages. The maximum officially supported Ø2 (primary) clock speed is 14
295:
hardware description model is available for designing the W65C02S core into an
2667:
2662:
2643:
2604:
2593:
2588:
2583:
2559:
2295:
2154:
2089:
1874:
1794:
1752:
1740:
1163:
908:
833:
747:
608:
588:
145:
103:
41:
1630:
if bit 1 of the byte at zero-page address $ 12 is set. Some assemblers treat
1307:
as well as any code needed to save the value of the accumulator, typically a
939:
and it was implemented in parts manufactured since June 1976. The absence of
1845:
1800:
1772:
1762:
1746:
1736:
1021:
806:
706:
603:
575:
1490:. In both cases, the Z flag in the status register indicates the result of
2126:
2057:
1810:
1776:
175:
2138:
N, V, and Z flags were incorrect after decimal operation (but C was ok).
1766:
1682:
In contrast, in the 65C02, interrupt code could be written by having a
795:
292:
717:
Die photograph of a
Sitronix ST2064B microcontroller showing embedded
2439:; 1st Ed; David Eyes and Ron Lichty; Prentice Hall; 636 pages; 1986;
891:
696:
242:
17:
1759:(2 MHz 65SC12 plus optional 4 MHz 65C102 second processor)
2368:
31:, a name used on two other variants of the original 6502 processor.
2480:
2434:
2100:
1781:
1558:
which sets bit 1 in zero-page address $ 12. Some assemblers treat
712:
230:
195:
149:
28:
912:
s. 6502 programs using those opcodes will not work on the 65C02.
1043:
When executing a read-modify-write (R-M-W) instruction, such as
989:
will fetch the most significant byte of the target address from
319:
141:
2484:
906:
instruction. Those which remain truly unused are equivalent to
828:
The W65C02S may be operated at any convenient supply voltage (V
1001:
would get the least significant byte of the target address at
920:
The original 6502 had several errata when initially launched.
331:
327:
214:
1615:
is clear (BBR) or set (BBS). As with RMB and SMB above, the
1210:
function from the table above, one would store 4 in X, then
841:
at 5 volts, assuming the supporting hardware will allow it.
1859:, Novag Super Constellation, Fidelity Elite (4–20 MHz)
1722:
02 is a variant of the WDC 65C02 without bit instructions.
1654:
In addition to the new commands above, WDC also added the
318:
is the production version as of 2023, and is available in
1005:
and the most significant byte of the target address from
171:
applications, including medical-grade implanted devices.
2187:
2185:
2183:
2181:
2168:
2166:
2164:
1462:
are set (TSB) or cleared (TRB) according to the mask in
1340:, thereby changing the accumulator contents, then using
1939:
1937:
1935:
1933:
1931:
1929:
1927:
970:(most significant byte) and load those values into the
280:, varying between one and three bytes per instruction.
1784:
Modern
Replica of the MOS/CBM KIM-1 by Briel Computing
927:(rotate right) instruction, even though they did have
1166:
that can be accessed using an index. For instance, a
950:. In this addressing mode, the target address of the
2676:
2641:
2625:
2603:
2569:
2516:
1707:
1699:
1695:
1691:
1687:
1683:
1671:
1665:
1502:
1483:
1475:
1471:
1467:
1425:
1418:
1414:
1379:
1304:
1300:
1207:
1191:
1187:
1179:
1175:
1171:
1158:One common use for indirect addressing is to build
1135:
117:
112:
98:
93:
77:
59:
54:
1965:. Vol. 3, no. 10. June 1983. p. 199
849:is sufficient to support the frequency. Designer
780:) instructions reduce power consumption, decrease
252:. The register set is small, with a single 8-bit
2419:List of books about 65xx microprocessor families
1482:, whereas TRB stores the results of the logical
1151:would read those two bytes, construct the value
977:The bug appears when the vector address ends in
2058:"The 6502/65C02/65C816 Instruction Set Decoded"
1028:instruction (CLear Decimal) in almost all 6502
784:and enable synchronization with external events
2127:"Differences between NMOS 6502 and CMOS 65c02"
2121:
2119:
1358:unless a page is crossed which would make the
1303:can reduce code size, both by eliminating the
1050:, all NMOS variants will do a double write on
163:systems. The 65C02 has also been used in some
2496:
2345:"LASER 128 / 128EX / 128EX2 Video Technology"
2001:
1819:handhelds (KS5360 (65SC02 core) @ 4 MHz)
1662:instructions for supporting low-power modes.
1054:, first rewriting the current value found at
8:
1634:as part of the instruction's operand, e.g.,
1562:as part of the instruction's operand, e.g.,
1445:, Test and Set Bits and Test and Reset Bits.
923:Early 1975 versions of the processor had no
2077:"Extra Instructions Of The 65XX Series CPU"
819:allows stopping the clock to conserve power
801:Current consumption (core) of 0.15 and 1.5
202:produced a further modified version as the
2503:
2489:
2481:
2148:
2146:
1611:if the selected bit of the zero page byte
1263:. Some assemblers use the alternate forms
1122:. This performs pointer-offset addressing.
962:would fetch the value in memory locations
646:(providing an address space of 64 KB)
40:
2475:6502/65C02/65C816 Instruction Set Decoded
2399:Taylor, Simon; Watford, Bob (July 1984).
1877:, a further enhanced version of the 65C02
311:(ICE) and a software development system.
229:The 65C02 is a low cost, general-purpose
2429:; Western Design Center; 32 pages; 2018.
1923:
1887:
1424:In addition to the enhancements of the
1079:prior to the value of X being added to
297:application-specific integrated circuit
198:later licensed the design as well, and
2250:. GTE Microcircuits. 1984. p. 1-3
2232:
2203:
2191:
2172:
1943:
344:
36:
34:CMOS microprocessor in the 6502 family
2015:"6502 CPU Projects in HDL (for FPGA)"
1837:home computer (65C02 @ 4.09 MHz)
1765:by Briel Computers, a replica of the
1474:and stores the result of the logical
832:) between 1.8 and 5 volts (±5%). The
7:
1626:which branches to the address label
1513:Rockwell-specific instructions are:
1454:) is logically ANDed with memory at
2550:(and 6510T, 6512, 6513, 6514, 6515)
1194:one would use something similar to
49:microprocessor in a PDIP-40 package
2477:– From Neil Parker's Apple II page
2437:- including the 6502, 65C02, 65802
1848:home computer (65C02 @ 3 MHz)
1749:by Apple Computer (1.023 MHz)
1536:. Set or Reset (clear) bit number
1155:, and then jump to that location.
1013:. The 65C02 corrected this issue.
25:
2101:"ROR" in Microsoft BASIC for 6502
1813:handhelds (6 MHz) by Timetop
1350:, branch always. Operates like a
993:of the original page rather than
886:Undocumented instructions removed
809:at 1.89 V and 5.25 V respectively
2112:File:MCS650x Instruction Set.jpg
1170:might list the entry points for
1984:Koehn, Philipp (2 March 2018).
1797:handheld (65SC02 @ ~4 MHz)
2075:Vardy, Adam (22 August 1995).
1769:hobbyist computer (1 MHz)
1755:home/educational computer, by
1067:, followed by a single write.
754:instruction is being processed
1:
2633:Interrupts in 65xx processors
2469:65xx/65Cxx/65SCxx Differences
1870:Interrupts in 65xx processors
1371:Bit manipulation instructions
1218:New and modified instructions
1162:, a list of entry points for
981:, which is the boundary of a
966:(least significant byte) and
872:Comparison with the NMOS 6502
798:specified at 1.71 V to 5.25 V
301:field-programmable gate array
2529:(and 6501, 6503, 6504, 6505)
2386:Wagner, Robert (June 1983).
1118:, This reads the value from
845:crystal), etc., as long as V
746:) output indicates to other
2321:"BBC Master Acorn Computer"
2247:GTE Microcircuits Date Book
2062:Neil Parker's Apple II page
1450:A mask in the accumulator (
65:; 41 years ago
2731:
2416:
2369:"HuC6280 - Archaic Pixels"
2090:The 6502 Rotate Right Myth
2029:"W65C02DB Developer Board"
1686:followed immediately by a
1602:. Branch on Bit Set/Reset.
958:instruction. For example,
562:
547:
538:
462:
441:
26:
2002:Taylor & Watford 1984
1726:Notable uses of the 65C02
1702:and handled the request.
1694:to the handler. When the
1466:. TSB performs a logical
1398:may be used in place of:
571:
523:
488:
485:
474:
471:
451:
448:
225:Introduction and features
108:1 MHz to 14 MHz
39:
1075:will do a dummy read on
735:) output indicates when
27:Not to be confused with
2465:- Western Design Center
2405:Personal Computer World
1364:memory management units
1292:. Replaces the need to
1099:Indexed indirect, e.g.
997:of the new page. Hence
721:core in the upper right
144:version of the popular
2556:(and 7501, 8500, 8501)
2274:. Sybex. p. 348.
1497:before the content of
853:has pointed out that F
722:
631:General logic features
233:microprocessor (8-bit
188:Rockwell Semiconductor
2715:8-bit microprocessors
2571:Western Design Center
2349:www.old-computers.com
2325:www.old-computers.com
2268:Zaks, Rodnay (1983).
863:printed circuit board
716:
695:, implemented by 212
651:arithmetic logic unit
159:roles and industrial
131:Western Design Center
85:Western Design Center
2710:65xx microprocessors
2271:Programming the 6502
1743:(NCR 1.023 MHz)
1182:, etc in a table at
1114:contains the vector
1091:New addressing modes
2407:. pp. 174–175.
2394:. pp. 199–204.
2217:"W65C02S Datasheet"
2206:, pp. 200–201.
1803:aka TurboGrafx-16 (
1789:Video game consoles
1757:Acorn Computers Ltd
948:indirect addressing
789:Electrical features
739:are being addressed
658:processor registers
347:
309:in-circuit emulator
153:MOS Technology 6502
122:MOS Technology 6502
78:Common manufacturer
55:General information
1962:Softalk Publishing
1833:cartridge for the
1817:Watara Supervision
1747:Enhanced Apple IIe
1540:in zero page byte
1470:after the logical
1030:interrupt handlers
877:Basic architecture
723:
345:
2697:
2696:
2452:
2296:"8-The Apple IIc"
1775:series clones of
1106:Indirect indexed
824:Clocking features
782:interrupt latency
752:read-modify-write
737:interrupt vectors
628:
627:
624:
623:
184:GTE Microcircuits
157:portable computer
127:
126:
16:(Redirected from
2722:
2505:
2498:
2491:
2482:
2448:
2433:Programming the
2408:
2395:
2388:"Assembly Lines"
2373:
2372:
2365:
2359:
2358:
2356:
2355:
2341:
2335:
2334:
2332:
2331:
2317:
2311:
2310:
2308:
2307:
2300:Apple II History
2292:
2286:
2285:
2265:
2259:
2258:
2256:
2255:
2242:
2236:
2230:
2224:
2223:
2221:
2213:
2207:
2201:
2195:
2189:
2176:
2170:
2159:
2158:
2150:
2141:
2140:
2135:
2133:
2123:
2114:
2109:
2103:
2098:
2092:
2087:
2081:
2080:
2072:
2066:
2065:
2053:
2047:
2046:
2039:
2033:
2032:
2025:
2019:
2018:
2011:
2005:
1999:
1993:
1992:
1990:
1981:
1975:
1974:
1972:
1970:
1953:
1947:
1941:
1906:
1902:
1896:
1892:
1842:second processor
1807:@ 7.16 MHz)
1709:
1701:
1697:
1693:
1689:
1685:
1673:
1667:
1661:
1657:
1644:
1625:
1601:
1587:
1569:
1557:
1535:
1525:
1504:
1496:
1485:
1477:
1473:
1469:
1465:
1453:
1444:
1437:
1427:
1420:
1416:
1409:
1404:
1394:
1389:
1381:
1361:
1357:
1353:
1349:
1343:
1339:
1335:
1331:
1327:
1323:
1319:
1313:
1310:
1306:
1302:
1298:
1288:, STore Zero in
1287:
1278:
1274:
1270:
1266:
1262:
1255:
1248:
1244:
1240:
1236:
1232:
1228:
1213:
1209:
1201:
1197:
1193:
1189:
1185:
1181:
1177:
1173:
1154:
1150:
1146:
1142:
1137:
1130:
1121:
1117:
1113:
1109:
1102:
1082:
1078:
1074:
1049:
1027:
1012:
1008:
1004:
1000:
996:
992:
988:
985:. In this case,
980:
969:
965:
961:
957:
953:
942:
938:
934:
930:
926:
911:
905:
817:static circuitry
779:
767:
745:
734:
703:addressing modes
352:
351:
348:
346:65C02 registers
267:
263:
167:, as well as in
73:
71:
66:
44:
37:
21:
2730:
2729:
2725:
2724:
2723:
2721:
2720:
2719:
2700:
2699:
2698:
2693:
2672:
2637:
2621:
2599:
2565:
2512:
2511:65xx-based CPUs
2509:
2459:
2426:65C02 Datasheet
2421:
2415:
2413:Further reading
2398:
2385:
2382:
2377:
2376:
2367:
2366:
2362:
2353:
2351:
2343:
2342:
2338:
2329:
2327:
2319:
2318:
2314:
2305:
2303:
2294:
2293:
2289:
2282:
2267:
2266:
2262:
2253:
2251:
2244:
2243:
2239:
2231:
2227:
2219:
2215:
2214:
2210:
2202:
2198:
2190:
2179:
2171:
2162:
2155:"65C02 Opcodes"
2152:
2151:
2144:
2131:
2129:
2125:
2124:
2117:
2110:
2106:
2099:
2095:
2088:
2084:
2074:
2073:
2069:
2055:
2054:
2050:
2041:
2040:
2036:
2027:
2026:
2022:
2013:
2012:
2008:
2000:
1996:
1988:
1983:
1982:
1978:
1968:
1966:
1955:
1954:
1950:
1942:
1925:
1920:
1915:
1910:
1909:
1903:
1899:
1893:
1889:
1884:
1866:
1853:chess computers
1851:many dedicated
1846:Acorn BBC Micro
1840:Tube-connected
1826:
1791:
1733:
1728:
1716:
1659:
1655:
1652:
1650:Low-power modes
1635:
1620:
1589:
1575:
1563:
1555:
1550:zero page. The
1527:
1517:
1491:
1463:
1451:
1439:
1432:
1407:
1402:
1392:
1387:
1373:
1359:
1355:
1351:
1347:
1341:
1337:
1333:
1329:
1325:
1321:
1317:
1311:
1308:
1293:
1282:
1276:
1272:
1268:
1264:
1257:
1250:
1246:
1242:
1238:
1234:
1230:
1226:
1220:
1211:
1199:
1195:
1183:
1152:
1148:
1144:
1143:holds $ 34 and
1140:
1128:
1119:
1115:
1111:
1107:
1100:
1093:
1080:
1076:
1072:
1044:
1025:
1010:
1006:
1002:
998:
994:
990:
986:
978:
972:program counter
967:
963:
959:
955:
951:
940:
936:
932:
928:
924:
918:
907:
903:
888:
879:
874:
860:
856:
848:
840:
831:
826:
791:
777:
765:
743:
732:
728:
697:operation codes
687:program counter
679:status register
674:index registers
633:
565:Status register
541:Program counter
495:Index Register
481:Index Register
465:Index registers
432:
427:
422:
417:
412:
407:
402:
397:
392:
387:
382:
377:
372:
367:
362:
357:
305:developer board
288:(SoC) designs.
278:instruction set
265:
261:
258:index registers
256:(A), two 8-bit
246:program counter
227:
161:microcontroller
140:is an enhanced
89:
69:
67:
64:
50:
35:
32:
23:
22:
15:
12:
11:
5:
2728:
2726:
2718:
2717:
2712:
2702:
2701:
2695:
2694:
2692:
2691:
2686:
2680:
2678:
2674:
2673:
2671:
2670:
2665:
2660:
2655:
2653:Hudson HuC6280
2649:
2647:
2639:
2638:
2636:
2635:
2629:
2627:
2623:
2622:
2620:
2619:
2613:
2611:
2601:
2600:
2598:
2597:
2591:
2586:
2581:
2575:
2573:
2567:
2566:
2564:
2563:
2557:
2551:
2545:
2540:
2535:
2530:
2523:
2521:
2518:MOS Technology
2514:
2513:
2510:
2508:
2507:
2500:
2493:
2485:
2479:
2478:
2472:
2466:
2458:
2457:External links
2455:
2454:
2453:
2445:978-0893037895
2430:
2414:
2411:
2410:
2409:
2401:"6502 revival"
2396:
2381:
2378:
2375:
2374:
2360:
2336:
2312:
2287:
2280:
2260:
2237:
2235:, p. 199.
2225:
2208:
2196:
2194:, p. 203.
2177:
2175:, p. 200.
2160:
2153:Clark, Bruce.
2142:
2115:
2104:
2093:
2082:
2067:
2056:Parker, Neil.
2048:
2034:
2020:
2006:
2004:, p. 174.
1994:
1976:
1948:
1946:, p. 204.
1922:
1921:
1919:
1916:
1914:
1911:
1908:
1907:
1897:
1886:
1885:
1883:
1880:
1879:
1878:
1872:
1865:
1862:
1861:
1860:
1849:
1838:
1825:
1824:Other products
1822:
1821:
1820:
1814:
1808:
1798:
1790:
1787:
1786:
1785:
1779:
1770:
1760:
1750:
1744:
1741:Apple Computer
1732:
1731:Home computers
1729:
1727:
1724:
1715:
1712:
1651:
1648:
1647:
1646:
1604:
1603:
1572:
1571:
1546:
1545:
1507:
1506:
1447:
1446:
1411:
1410:
1408:AND #%00010000
1405:
1396:
1395:
1393:BIT #%00010000
1390:
1372:
1369:
1368:
1367:
1345:
1315:
1280:
1219:
1216:
1212:JMP ($ A000,X)
1124:
1123:
1104:
1092:
1089:
917:
914:
887:
884:
878:
875:
873:
870:
858:
854:
846:
838:
829:
825:
822:
821:
820:
813:
810:
799:
790:
787:
786:
785:
755:
740:
727:
726:Logic features
724:
711:
710:
699:
689:
683:
682:
681:
676:
671:
666:
654:
647:
640:
632:
629:
626:
625:
622:
621:
611:
606:
601:
596:
591:
586:
583:
578:
573:
569:
568:
560:
559:
549:
545:
544:
536:
535:
525:
522:
519:
516:
513:
510:
507:
504:
501:
497:
496:
490:
487:
483:
482:
476:
473:
469:
468:
460:
459:
453:
450:
446:
445:
443:Main registers
439:
438:
436:(bit position)
433:
430:
428:
425:
423:
420:
418:
415:
413:
410:
408:
405:
403:
400:
398:
395:
393:
390:
388:
385:
383:
380:
378:
375:
373:
370:
368:
365:
363:
360:
358:
355:
286:system-on-chip
226:
223:
165:home computers
138:microprocessor
125:
124:
119:
115:
114:
110:
109:
106:
96:
95:
91:
90:
88:
87:
81:
79:
75:
74:
61:
57:
56:
52:
51:
45:
33:
24:
14:
13:
10:
9:
6:
4:
3:
2:
2727:
2716:
2713:
2711:
2708:
2707:
2705:
2690:
2687:
2685:
2682:
2681:
2679:
2675:
2669:
2666:
2664:
2661:
2659:
2658:Nintendo SA-1
2656:
2654:
2651:
2650:
2648:
2645:
2640:
2634:
2631:
2630:
2628:
2624:
2618:
2615:
2614:
2612:
2610:
2606:
2602:
2595:
2592:
2590:
2587:
2585:
2582:
2580:
2577:
2576:
2574:
2572:
2568:
2561:
2558:
2555:
2552:
2549:
2546:
2544:
2541:
2539:
2536:
2534:
2531:
2528:
2525:
2524:
2522:
2519:
2515:
2506:
2501:
2499:
2494:
2492:
2487:
2486:
2483:
2476:
2473:
2470:
2467:
2464:
2463:65C02 webpage
2461:
2460:
2456:
2451:
2446:
2442:
2438:
2436:
2431:
2428:
2427:
2423:
2422:
2420:
2412:
2406:
2402:
2397:
2393:
2389:
2384:
2383:
2379:
2370:
2364:
2361:
2350:
2346:
2340:
2337:
2326:
2322:
2316:
2313:
2301:
2297:
2291:
2288:
2283:
2277:
2273:
2272:
2264:
2261:
2249:
2248:
2241:
2238:
2234:
2229:
2226:
2218:
2212:
2209:
2205:
2200:
2197:
2193:
2188:
2186:
2184:
2182:
2178:
2174:
2169:
2167:
2165:
2161:
2156:
2149:
2147:
2143:
2139:
2128:
2122:
2120:
2116:
2113:
2108:
2105:
2102:
2097:
2094:
2091:
2086:
2083:
2078:
2071:
2068:
2063:
2059:
2052:
2049:
2044:
2038:
2035:
2030:
2024:
2021:
2016:
2010:
2007:
2003:
1998:
1995:
1987:
1980:
1977:
1964:
1963:
1958:
1952:
1949:
1945:
1940:
1938:
1936:
1934:
1932:
1930:
1928:
1924:
1917:
1912:
1901:
1898:
1891:
1888:
1881:
1876:
1873:
1871:
1868:
1867:
1863:
1858:
1854:
1850:
1847:
1843:
1839:
1836:
1832:
1828:
1827:
1823:
1818:
1815:
1812:
1809:
1806:
1802:
1801:NEC PC Engine
1799:
1796:
1793:
1792:
1788:
1783:
1780:
1778:
1774:
1771:
1768:
1764:
1761:
1758:
1754:
1751:
1748:
1745:
1742:
1738:
1735:
1734:
1730:
1725:
1723:
1721:
1713:
1711:
1703:
1680:
1678:
1669:
1663:
1649:
1643:
1639:
1633:
1629:
1624:
1618:
1614:
1610:
1606:
1605:
1600:
1596:
1593:
1586:
1582:
1579:
1574:
1573:
1567:
1561:
1553:
1548:
1547:
1543:
1539:
1534:
1531:
1524:
1521:
1516:
1515:
1514:
1511:
1500:
1495:
1489:
1481:
1461:
1457:
1449:
1448:
1443:
1436:
1431:
1430:
1429:
1422:
1406:
1401:
1400:
1399:
1391:
1386:
1385:
1384:
1377:
1370:
1365:
1346:
1316:
1297:
1291:
1286:
1281:
1261:
1254:
1225:
1224:
1223:
1217:
1215:
1203:
1169:
1168:device driver
1165:
1161:
1160:branch tables
1156:
1132:
1105:
1098:
1097:
1096:
1090:
1088:
1084:
1068:
1066:
1061:
1057:
1053:
1048:
1041:
1038:
1033:
1031:
1023:
1019:
1014:
984:
975:
973:
949:
944:
921:
915:
913:
910:
900:
896:
893:
885:
883:
876:
871:
869:
866:
864:
852:
842:
835:
823:
818:
814:
811:
808:
804:
800:
797:
793:
792:
788:
783:
775:
771:
763:
759:
756:
753:
749:
742:Memory lock (
741:
738:
731:Vector pull (
730:
729:
725:
720:
715:
708:
704:
700:
698:
694:
690:
688:
684:
680:
677:
675:
672:
670:
669:stack pointer
667:
665:
662:
661:
659:
655:
652:
648:
645:
641:
639:
635:
634:
630:
619:
615:
612:
610:
607:
605:
602:
600:
597:
595:
592:
590:
587:
584:
582:
579:
577:
574:
570:
567:
566:
561:
557:
553:
550:
546:
543:
542:
537:
533:
529:
526:
520:
517:
514:
511:
508:
505:
502:
499:
498:
494:
491:
484:
480:
477:
470:
467:
466:
461:
457:
454:
447:
444:
440:
437:
434:
429:
424:
419:
414:
409:
404:
399:
394:
389:
384:
379:
374:
369:
364:
359:
354:
353:
350:
349:
343:
341:
337:
333:
329:
325:
321:
317:
312:
310:
306:
302:
298:
294:
289:
287:
281:
279:
275:
274:stack pointer
271:
259:
255:
251:
247:
244:
240:
236:
232:
224:
222:
220:
216:
212:
207:
205:
201:
197:
193:
189:
185:
181:
177:
172:
170:
166:
162:
158:
154:
151:
147:
143:
139:
136:
132:
123:
120:
116:
111:
107:
105:
102:
97:
92:
86:
83:
82:
80:
76:
62:
58:
53:
48:
43:
38:
30:
19:
2689:Chuck Peddle
2626:Architecture
2596:(and 65C802)
2578:
2432:
2424:
2404:
2391:
2380:Bibliography
2363:
2352:. Retrieved
2348:
2339:
2328:. Retrieved
2324:
2315:
2304:. Retrieved
2302:. 2010-06-23
2299:
2290:
2270:
2263:
2252:. Retrieved
2246:
2240:
2228:
2211:
2199:
2137:
2130:. Retrieved
2107:
2096:
2085:
2070:
2061:
2051:
2043:"W65C02S-14"
2037:
2023:
2009:
1997:
1986:"6502 Stack"
1979:
1967:. Retrieved
1960:
1951:
1900:
1890:
1857:Mephisto MMV
1835:Commodore 64
1829:TurboMaster
1739:portable by
1719:
1717:
1704:
1681:
1670:
1664:
1653:
1641:
1637:
1631:
1627:
1622:
1616:
1612:
1608:
1598:
1594:
1591:
1584:
1580:
1577:
1565:
1559:
1551:
1541:
1537:
1532:
1529:
1522:
1519:
1512:
1508:
1498:
1493:
1487:
1479:
1459:
1455:
1441:
1434:
1423:
1412:
1397:
1378:
1374:
1295:
1289:
1284:
1259:
1252:
1221:
1204:
1196:JMP ($ A004)
1157:
1149:JMP ($ A000)
1147:holds $ 12,
1133:
1125:
1108:LDA ($ 10),Y
1101:LDA ($ 10,X)
1094:
1085:
1073:LDA $ 1200,X
1069:
1064:
1059:
1055:
1051:
1046:
1042:
1037:decimal mode
1034:
1015:
1009:rather than
999:JMP ($ 12FF)
976:
960:JMP ($ 1234)
945:
922:
919:
901:
897:
889:
880:
867:
843:
827:
773:
769:
761:
757:
718:
705:, including
693:instructions
617:
613:
563:
555:
551:
539:
531:
527:
492:
478:
463:
455:
442:
435:
315:
313:
299:(ASIC) or a
290:
282:
228:
218:
208:
191:
173:
134:
128:
46:
2684:Bill Mensch
2471:- CPU World
2233:Wagner 1983
2204:Wagner 1983
2192:Wagner 1983
2173:Wagner 1983
2132:27 February
1944:Wagner 1983
1831:accelerator
1294:LDA #0;STA
1164:subroutines
1134:The 6502's
983:memory page
851:Bill Mensch
748:bus masters
664:accumulator
644:address bus
458:ccumulator
340:static core
254:accumulator
250:address bus
200:Seiko Epson
118:Predecessor
94:Performance
2704:Categories
2668:Ricoh 5A22
2663:Ricoh 2A03
2617:740 family
2605:Mitsubishi
2562:(and 4510)
2417:See also:
2354:2023-10-31
2330:2023-10-31
2306:2023-10-31
2281:0895881357
2254:2024-05-02
1913:References
1875:CSG 65CE02
1795:Atari Lynx
1753:BBC Master
1621:BBS1 $ 12,
1403:LDA $ 1234
1388:LDA $ 1234
1129:LDA ($ 10)
834:data sheet
764:nterrupt (
709:addressing
316:W65C02S–14
219:W65C02S-14
104:clock rate
2677:Designers
2450:(archive)
1957:"Softalk"
1918:Citations
1773:Laser 128
1763:Replica 1
1737:Apple IIc
1556:SMB1 $ 12
1112:$ 10/$ 11
1022:interrupt
916:Bug fixes
707:zero page
241:) with a
235:registers
2646:machines
2392:Softtalk
1864:See also
1844:for the
1811:GameKing
1777:Apple II
1677:spinning
638:data bus
620:egister
336:homebrew
239:data bus
176:Synertek
169:embedded
60:Launched
2609:Renesas
1855:, e.g.
1805:HuC6280
1767:Apple I
1492:.A AND
1035:During
892:opcodes
865:space.
796:voltage
794:Supply
760:it-for-
750:when a
719:W65C02S
685:16-bit
642:16-bit
572:
558:ounter
554:rogram
534:ointer
486:
472:
449:
293:Verilog
204:HuC6280
148:-based
113:History
68: (
47:W65C02S
2594:65C816
2589:65C265
2584:65C134
2560:65CE02
2443:
2278:
1969:24 May
1718:The 65
1714:65SC02
1640:,$ 12,
1200:$ A000
1184:$ A000
1153:$ 1234
1145:$ A001
1141:$ A000
1120:$ 1005
1116:$ 1000
1081:$ 1200
1077:$ 1200
1011:$ 1300
1007:$ 1200
1003:$ 12FF
968:$ 1235
964:$ 1234
815:Fully
768:) and
656:8-bit
649:8-bit
636:8-bit
616:tatus
266:$ 00FF
262:$ 0000
243:16-bit
192:W65C02
186:, and
133:(WDC)
2579:65C02
2520:, CSG
2435:65816
2220:(PDF)
1989:(PDF)
1905:page.
1895:date.
1882:Notes
1782:KIM-1
1568:,$ 12
1314:pair.
1277:DEC A
1273:INC A
1176:CLOSE
1018:reset
653:(ALU)
530:tack
307:, an
270:stack
231:8-bit
196:Sanyo
150:8-bit
135:65C02
99:Max.
29:6502C
18:65C02
2644:game
2642:For
2554:8502
2548:6510
2543:6509
2538:6508
2533:6507
2527:6502
2441:ISBN
2276:ISBN
2134:2018
1971:2022
1658:and
1642:addr
1636:BBS
1632:bit#
1628:addr
1623:addr
1617:bit#
1609:addr
1599:addr
1592:bit#
1588:and
1585:addr
1578:bit#
1564:SMB
1560:bit#
1552:bit#
1538:bit#
1530:bit#
1526:and
1520:bit#
1499:addr
1494:addr
1488:addr
1480:addr
1460:addr
1456:addr
1442:addr
1440:TRB
1438:and
1435:addr
1433:TSB
1413:The
1296:addr
1290:addr
1285:addr
1283:STZ
1260:addr
1258:DEC
1253:addr
1251:INC
1249:and
1229:and
1208:READ
1192:READ
1188:READ
1180:READ
1172:OPEN
1065:addr
1060:addr
1056:addr
1052:addr
1047:addr
1045:INC
995:$ 00
991:$ 00
979:$ FF
805:per
326:and
324:PLCC
320:PDIP
314:The
248:and
237:and
213:and
211:PLCC
146:nMOS
142:CMOS
129:The
70:1983
63:1983
1708:WAI
1700:JSR
1696:WAI
1692:JMP
1690:or
1688:JSR
1684:WAI
1672:WAI
1666:STP
1660:WAI
1656:STP
1590:BBR
1576:BBS
1528:RMB
1518:SMB
1503:BIT
1486:at
1484:AND
1478:at
1472:AND
1426:BIT
1419:BIT
1415:AND
1380:BIT
1360:BRA
1356:JMP
1352:JMP
1348:BRA
1342:PHA
1338:TYA
1336:or
1334:TXA
1330:PLY
1326:PHY
1322:PLX
1318:PHX
1312:PLA
1309:PHA
1305:LDA
1301:STZ
1271:or
1269:DEA
1265:INA
1247:DEY
1243:INY
1239:DEX
1235:INX
1231:DEC
1227:INC
1136:JMP
1026:CLD
1020:or
987:JMP
956:JMP
952:JMP
941:ROR
937:ROR
933:ROR
929:ROL
925:ROR
909:NOP
904:BBS
859:MAX
855:MAX
807:MHz
778:STP
766:WAI
744:MLB
733:VPB
701:16
691:69
548:PC
524:SP
332:MHz
328:QFP
264:to
215:QFP
180:NCR
101:CPU
2706::
2607:,
2447:.
2403:.
2390:.
2347:.
2323:.
2298:.
2180:^
2163:^
2145:^
2136:.
2118:^
2060:.
1959:.
1926:^
1720:SC
1613:zp
1595:zp
1581:zp
1542:zp
1533:zp
1523:zp
1476:OR
1468:OR
1464:.A
1452:.A
1202:.
1186:.
1178:,
1174:,
847:DD
839:DD
830:DD
803:mA
770:ST
758:WA
660::
585:-
521:1
518:0
515:0
512:0
509:0
506:0
503:0
500:0
489:Y
475:X
452:A
322:,
291:A
206:.
194:.
182:,
178:,
2504:e
2497:t
2490:v
2371:.
2357:.
2333:.
2309:.
2284:.
2257:.
2222:.
2157:.
2079:.
2064:.
2045:.
2031:.
2017:.
1991:.
1973:.
1675:"
1638:1
1597:,
1583:,
1566:1
1544:.
1366:.
1344:.
1328:,
1324:,
1320:,
1279:.
1275:/
1267:/
1256:/
1245:/
1241:,
1237:/
776:(
774:P
772:o
762:I
618:R
614:S
609:C
604:Z
599:I
594:D
589:B
581:V
576:N
556:C
552:P
532:P
528:S
493:Y
479:X
456:A
431:0
426:1
421:2
416:3
411:4
406:5
401:6
396:7
391:8
386:9
381:0
376:1
371:2
366:3
361:4
356:5
72:)
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
