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65c02 jump table com 3. Posted: Wed Jul 01, 2020 7:15 pm . add 1 cycle on conditional branches if taken. All times are UTC It is currently Wed Nov 06, 2024 4:54 am: View unanswered posts | View active topics. word addr3 [] idea5: // index in A [2] ASL A [2] TAX [6] JMP (table,X) Cycles: 2+2+6=10. Register values are loaded with the Here I'm using the "+" symbol in 6502 code to have the assembler access the low byte ("+0", which is pointless but helps convey that this is a multi-byte variable) and the high In C/C++ a switch statement can be lowered by the compiler to a jump table. For x86 (And "Eyes & Lichty" is scene slang for the excellent manual "Programming the 65816 Including the 6502, 65C02, and 65802" by David Eyes & Ron Lichty. &00575F06[25] have been added for ease On the table. It may help to have a small size type (like unsigned char) for the expression, or to The 6502/65C02/65C816 Instruction Set Decoded. On the 65C02, this can be done with: Jan 7, 2025 · In its basic form, this mode is available for the JMP instruction only. an inner interpreter). Oct 25, 2022 · JMP - Jump. On the 65c816, there This code could easily use a jump table because we can come up with the instructions for each body of the switch statement and just put them into the jump table, one at WDC sent me the W65C02SXB and the W65c816SXB, two single board computers based on the 65C02 and the 65C816, respectively. It uses less power than the original 6502, Mar 9, 2018 · . Things look good until a game was loaded, whereupon it fell over unceremoniously. 65CE02: Extension of the 65C02, used in the C65. Therefore al = 10h. (The 6502 decimal mode and indirect jump bugs are fixed without requiring the extra cycle that the 65C02 requires. All times are UTC It is currently Wed Nov 06, 2024 5:06 am: View unanswered posts | View active topics. Contribute to dbuchwald/6502 development by creating an account on GitHub. It aims to be compatible with the Boston System Office @Dr. g. My HBC-56, a 65C02/TMS9918A homebrew computer on a backplane, In computing, the reset vector is the default location a central processing unit will go to find the first instruction it will execute after a reset. 1 : Introduction: 1. ). LONGA OFF 10 . It behaves like JMP (addr), except it fetches the 16-bit value from addr+X. It uses less power than the original 6502, 5 days ago · Specifying 65C02 will use a few 65C02 instructions when generating code. Formally, BRK is a software interrupt that takes an 8-bit operand (the "signature"), like SWI in the MC6800 or INT in x86. 4k次，点赞2次，收藏12次。 65C02（Pinokio@163. All times are UTC 1 day ago · My project is a simple jump-table based emulator: the actual value of the opcode (let's say 0x80) is used to address a function pointer table, each entry of such table is a C++ function which emulates the behavior of the Sep 28, 2015 · Thanks to everyone who read over the early draft. google. Aug 23, 2001 · It is currently Sun Sep 29, 2024 3:57 am: View unanswered posts | View active topics. The compiler might decide to use a jump table and make a huge improvement in the case of 300+. Kameleon A switch with contiguous cases should spit out equivalent code, especially if you add default: __builtin_unreachable(); to try and coax the compiler not to Then to step through the table, just increment or decrement Y with the single-byte, two-clock instructions INY or DEY, instead of having to modify the address in ZP. LONGI OFF 4. Posted: Wed Jul 23, 2014 10:51 pm . Although the one address, accumulator-based architecture of the 6502/65C02 Tests for all valid opcodes of the 6502 and 65C02 processor - Klaus2m5/6502_65C02_functional_tests This is the source code of the 6502/65C02/65CE02 assembler developed and used by Commodore for the C65 project. L4[0+rdi*8]]，这行汇编有两 Oct 4, 2008 · 关于【CSAPP】 的介绍： CSAPP是一书的简称，中文版名称为，本书主要讲述的是计算机内部在运行程序的时候各个部分是如何协同进行工作的，让读者能够对计算机的运行机 Nov 23, 2019 · They replace the low 28 bits of the 32-bit PC, so they're absolute within a 256MB region. Page 1 of 1 [ 15 posts ] Previous topic | Next topic : Author Message; muchtolearn Post subject: Jump Tables. Here is a table of the available opcodes Jan 6, 2025 · Jump to navigation Jump to search. All times are UTC It is currently Wed Nov 06, 2024 5:01 am: View unanswered posts | View active topics. The following sections list the Oct 11, 2024 · Use Jump tables with RTS instruction instead of JMP indirect instruction. 2 : Review of twos complement (signed) numbers: 2 : Review of compare instructions: The 6502 and the Jan 8, 2025 · The JMP (addr,X) instruction is present in later 65xx processors (65C02, 65C802/65C816). (&00575F06[0 ] . A jump table contains addresses of goto - targets. org Users Forum » DelphiForums: 6502. jump table addresses are made up of addresses-1 when it is Apr 2, 2024 · Therefore, some programmers prefer to use a forced branch instead of a jump, using an approach like this: CLC ; clear the carry flag BCC SOMEWHERE ; branch if carry Most instructions within a group follow this support table, but there are some exceptions. Jump tables on the 6502 require you to either push the address you want to jump to onto the stack, or store it to an address before using an indirect jump. The jump table was stable from inception to the  · (Actually, the assembler currently it doesn't save a link to the replacement routines but an offset to a jump table with the addresses of those routines, which is an extra level of Feb 7, 2021 · Assuming you’re asking: what can the 6502 be seen to be doing by an external observer, then the data sheet has a full breakdown of bus activity per cycle per addressing  · It is currently Wed Nov 06, 2024 2:21 am: View unanswered posts | View active topics. Board index » 6502. We now show that the problem of minimizing the total size of jump The 6800 has 197 op codes compared to 65c02's 202. Sep 8, 2023 · MOS-6502, WDC-65C01, WDC-65815 instruction set Jan 6, 2023 · Suitable code for the 65C02 and 65C816 (with 8-bit index) is as follows IRQ PHX LDX IRQPORT JMP (IRQTABLE,X) IQRTABLE Address of service routine for IRQ0 This Indexed-indirect addressing mode is particularly useful for implementing jump tables, also known as branch tables, in assembly language. And yes, relative to the end of the jump = relative to the delay slot instruction address Aug 7, 2024 · Jump Table; Scanning Tables; Scanning Large Tables; Synthetic Instructions; Programming with unofficial opcodes; Pointer tables; Multibyte constant; Limitations; Sep 10, 2023 · Supports 6502, 65C02, R65C02, W65C02, 65CE02, 65816, DTV, 65EL02, 4510; Let's take a simple example of a low/high byte jump table of return addresses, this usually Jan 11, 2024 · This is fixed in some later chips like the 65C02 so for compatibility always ensure the indirect vector is not at the end of the page. For example if location $20 contains $31 and location $21 contains $65 Mar 9, 2002 · 65C02 Reference Manual Feel free to do whatever you want with this document, except claim that you did all the work of putting it together and HTMLizing it. Verilog isn't as popular as Jump tables. The Western Design Center (WDC), located in Mesa, Arizona, is a company which develops intellectual property for, and licenses manufacture of, MOS Technology 65xx based 65C02: Extension of the 6502. I've tried to make Oct 25, 2022 · Many 65C02 instruction can operate on memory locations specified indirectly through zero page. On the 65C02, this can be done with: Code: ASL TAX BCS L1 JMP (TABLE,X) Jan 1, 2025 · The range consists of data and is disassembled as a table of double words (32 bit values). The so-called RTS Trick is a method of implementing jump tables by pushing a subroutine's entry The Western Design Center (WDC) 65C02 microprocessor is an enhanced CMOS version of the popular nMOS-based 8-bit MOS Technology 6502. word addr1 . 1 : Types of comparisons: 1. ) Like the absolute JMP instruction it uses a 16-bit address (3 bytes in total), but takes two additional CPU cycles to  · The second one should be BRK instead of BRA. 9152 MHZ ADDED TO TABLES 158 ; 4) ASCI INIT STACK PROBLEM 159 ; 5) RESTORED Acc FOR ROUTINE If they are for sprite coordinates then you only need integer values and the easiest and fastest way is to compute all the possibilities first then store the results in a look-up table. Thanks to BigEd for the helpful feedback. 14 J <addr> - Jump to Address Jump to specified address. Joined: Wed Jul 01, 2020 6:15 pm Posts: 79 Location: Super NES / Super Famicom Software Development Kit - optixx/snes-sdk  · It is currently Sat Dec 21, 2024 11:21 am: View unanswered posts | View active topics. He was a major contributor to the design of the Motorola 6800 8-bit . &00575F06[25] have been added for ease (1) M65C02A core allows the 6502/65C02 index registers, X and Y, to be used as accumulators. The JSR instruction Dec 9, 2007 · 基本概念Jump Table 即跳转表，它可以理解为一个数组，如下图所示，数组的每一项存储一个目标地址，外部代码通过不同的索引从跳转表获取对应表项，得到目标地址，实现  · In looking at the datasheet for the 65C02, during a write cycle the output data lines are guaranteed to be active and valid at least 30ns before the fall of phi2, and 10ns after the Aug 2, 2018 · The 65816 is the successor to the 6502 and 65C02 (an improved version of the 6502) 8-bit microprocessor. All times are UTC DB6502: 65C02 based computer inspired by BE6502. Sets the program counter to the address specified by the operand. Macro assembler for the 6502, 65C02, 65816, 6800, 6809, 68000, 68010, Atari ASAP, PDP11, Atari Tom&Jerry DSP and generic pre-processor - DaveShepperd/macxx William David Mensch, Jr. (I suppose it turns out that using a decimal Tests for all valid opcodes of the 6502 and 65C02 processor - Klaus2m5/6502_65C02_functional_tests At the beginning of the level, it says which table you have to calculate with. A list of requirements is first, followed by a list of By contrast, with the X indexed jump, having an index in X, the X-indexed JUMP is executed (+6), and then when the operation completes, it Branches or Jumps back to the parsing routine Apr 3, 2004 · Table of Contents. General Overview The Western Design Oct 25, 2022 · JSR - Jump to Subroutine. This is a structured programming language for the 8-bit 6502/6510/65c02 microprocessor from the late 1970's and 1980's as used in many home computers from that era. com/p/snes-sdk - snes-sdk/opcodes_65c02_tables. It is a medium to low Mar 8, 2019 · Before the 65c02 came along with its JMP(abs,X) instruction, a way to do an indirect jump using a jump table with the NMOS 6502 was: ; Start with function (an even Jun 28, 2024 · EM_MOS_65C02: 0x00000008: MOS 65C02 generic additional instructions and addressing modes, including BRA, PHX, PHY, PLX, as defined in the RedPower CPU Nov 22, 2015 · Many commercial embedded designs have no need for ARM or MIPS performance, and the 65c02's low cost in silicon real estate and royalties keep it going into  · We catalogued many cores in this thread - there are a couple of late arrivals on the last page but I think the table in the head post is mostly complete. I noticed a difference of placement of the jump table between ARM and x86. If you know The jump table can be used by the compiler to optimize switch-case in many programming languages. Last edited by BigEd on Sat Sep 08, 2018 7:49 am, edited 1 time in total. `set a <(@(jmp_table + x) + y)` or `set z #42 & my_flag` compatible with py65mon's Sep 8, 2023 · MOS-6502, WDC-65C01, WDC-65815 opcodes Dec 23, 2013 · Does anyone know of a web page showing the differences between the NMOS 6502, the 65c02, and the '816? I have everything on paper, in different books and appendices Oct 25, 2022 · The Instruction Set. Jan 19, 2021 · Idea 5: Use 65C02 indexed indirect jump instruction table: . RTSTABLE. It may be the best unofficial textbook If we count 1c bytes into this table we get the value 10h. Organization. 65816: Extended 6502 with new Search or jump to Search code, repositories, users, issues, pull requests Search Clear. A highly successful and widespread microprocessor used in a range of computers like the Commodore 64 or the May 6, 2024 · On the CMOS 65c02, illegal op codes initially act as NOPs, but can be useful for single-cycle time delays, and more interestingly, for effectively extending the processor's  · As for the data sheet, they've done a poor job lining up the rows, and perhaps that's causing some confusion. This directive places the assembler in 65C02 processor mode. The subsequent EOR now produces ASCII 'C' in the accumulator; Automatically exported from code. Instructions These are conditional jumps, and  · Post subject: Re: 65C02 Opcode table. So, the 6502 would seem better for manipulating small tables A jump table is a table of code addresses, meant to be indexed by a selector value. al is now used as an index to the jump table at 56cd3f. Joined: Tue May  · flexible C-style expressions for addresses and values, including symbolic labels and flags, e. Admittedly, the 02's 32 op codes for BBS, BBR, too. add Find and fix vulnerabilities Codespaces. (born February 9, 1945) is an American electrical engineer born in Quakertown, Pennsylvania. Operation Opcodes Bytes Cycles Details Sort by Category. With a jump table you'd store target addresses The 65C02 and 65816 datasheets state that the N, V, and Z flags are valid as well as the C flag, but ironically, given the same inputs (carry flag, accumulator, and operand of the ADC or SBC 7 00:0000 CHIP 65C02 8 SPACES ON 9 . Don't expect too much from this option: In most cases the difference in size and speed is just 1-2%. Unofficial instructions. In my instruction tables, the msb of the Rockwell instructions DB6502: 65C02 based computer inspired by BE6502. Compilers do make optimizations over branches using various techniques like switch will get compiled to a jumptable just like you want as long as the label values aren't too sparse. e. Table of contents: 1 INTRODUCTION ; 2 MODES AND MEMORY ORGANIZATION Oct 17, 2020 · This must be accounted for when calculating branches or when pushing bytes to create a false return address (i. You access an item in a table by The total size of jump tables, and hence the total number of void entries in the tables, varies with the numbering function. The Info Opcodes Instructions Addressing Modes Table. The 65C02 processor supports all normal 6502 instructions plus new addressing modes and extra some Mar 3, 2014 · Thanks for this info. All times are UTC It is currently Wed Nov 06, 2024 4:58 am: View unanswered posts | View active topics. For example, if the number on the block is 10 and the table of 2 is indicated, you must jump on the block 5 times Now I wonder whether the artificial fall-back check default case will interfere with jump table generations? Imagine "ModeA" an "ModeB" etc are consecutive so the compiler If we count 1c bytes into this table we get the value 10h. The reset vector is a pointer or address, where the A jump table and your function table are basically the same - an array of addresses. Search or jump to Search code, repositories, users, 文章浏览阅读4. x86. The 6502 has a relatively basic set of instructions, many having similar functions (e. Verilog isn't as popular as Mar 7, 2023 · If a 65C02 board is going to be made to be compatible with plugging in a 65816, it needs to have a pull-up resister on a rarely used output line on the 65C02 that is an input on Sep 25, 2007 · The 65C02 has a 16 bit address space (64K) arranged in 256 pages each of which is 256 bytes long. word addr2 . The result of this addition,  · Another example, is a jump table with more than 128 addresses (e. All times are UTC Jun 28, 2022 · This must be accounted for when calculating branches or when pushing bytes to create a false return address (i. (Its generally use is jump vectors and jump tables. 16 bit relative address:  · Furthermore, the original W65C02 did not include the WAI and STP instructions introduced by WDC on the W65C816/W65C802 processors. Processor Status after use: Oct 17, 2020 · RTS is frequently used to implement a jump table where addresses-1 are pushed onto the stack and accessed via RTS eg. Page 0 ($0000-$00FF) has some special properties involving addressing Jan 29, 2020 · A 65C02 interprets $47 $83 as RMB4 $83 (as written in the listing), which clears bit 4 of that memory location. 65SC02: Small version of the 65C02 which lost a few opcodes again. All times are UTC Jan 7, 2025 · (Its generally use is jump vectors and jump tables. Search syntax tips. Joined: Sun Nov 08, 2009 1:56 am Posts: 391 Location: Minnesota I wrote: Quote: I've Sep 13, 2024 · 然后一个mov，这行mov的效果是，将rdi寄存器的高32位清零。最后，根据rdi寄存器的值，直接跳到jump table中的某个位置，jmp [QWORD PTR . Instant dev environments We catalogued many cores in this thread - there are a couple of late arrivals on the last page but I think the table in the head post is mostly complete. The only difference between both is how the 65C02 Debugger Last update: 10/10/2021 Bob Applegate bob@corshamtech. With this monitor, you can read and My contribution here is to explain that this doesn't have anything to do with jump tables mentioned in the title (IA32 Jump Table). Each switch case is defined as its memory address in the table jump. . Oct 25, 2022 · This mode has been added to the JMP instruction to support jump tables. JSR - Jump to Subroutine. org Users Forum » Programming. So we might have something like: Jul 27, 2004 · New 65C02 instructions take their 65C02 times. May 14, 2016 · The good news is the 65C02 has a Branch Always (BRA) opcode. ) Like the absolute JMP instruction it uses a 16-bit address (3 bytes in total), but takes two additional 65C02 emulator that runs on a 65C02. My take on Table 6-2 is that BE, D0-D7, RDY and SOB adhere to  · Another example, is a jump table with more than 128 addresses (e. For example if location $20 contains $31 and location $21 contains $65 Nov 15, 2024 · An infamous "feature" of the 6502 is that the JMP(abs) opcode will fetch the lower byte of the jump target from the address in the instruction, and fetch the upper byte of the jump It is currently Mon Sep 23, 2024 4:24 pm: View unanswered posts | View active topics. CMOS variants of the 6502 handle them completely differently, and later CPUs in the same family (e. 65C02, It is currently Wed Nov 06, 2024 5:18 am: View unanswered posts | View active topics. The program uses the selector to look up an address in the table, then jumps to that address. Branches can only jump by -128 to 127 bytes. All times are UTC Mar 28, 2024 · The familiar 65C02 instructions and address modes are retained, and some new ones are added. The value of the X register is added to the absolute location in the instruction to form the address. The JSR instruction pushes the address (minus one) of the return point on to the stack and then sets the program counter to the target memory Sep 11, 2024 · 65C02 Opcode table. It looks like it's quite difficult to program exactly what happens in each cycle. Page 1 of 2 [ 21 posts ] Go to page 1, 2 Next Previous topic | Next topic : Author Message; rwiker Post subject: 65C02 Opcode table. Check a complete 6502 reference for more details. All times are UTC Jan 6, 2023 · Table One gives a summary of the changes and additions used to accomplish zero-overhead high-level Forth interrupt response. c at master · uli/snes-sdk Aug 28, 2024 · 65C02（pinokio 译、编 2002-6-17）概要指令集寻址模式指令编码概要65C02有16位（64K）的地址空间分成256个页面，每个256字节。 0 页面($0000-$00FF)有一些很特别 Mar 6, 2024 · ¹ - Only available on WDC 65C02 ² - Only available on WDC and Rockwell 65C02 "*" : add 1 cycle if page boundary is crossed. so VIA2 will get polled before the RTI, and have SERVICE_VIA2 jump back to the fifth line above, so the ACIA would get The Western Design Center (WDC) 65C02 microprocessor is an enhanced CMOS version of the popular nMOS-based 8-bit MOS Technology 6502. com 译、编 2002-6-17） 概要 指令集 寻址模式 指令编码 概要65C02有16位（64K）的地址空间分成256个页面，每个256字  · A 6502 was replaced with a 65C02. Search or jump to Search code, repositories, users, It is currently Wed Nov 06, 2024 4:55 am: View unanswered posts | View active topics. Posted: Tue Sep 05, 2017 2:01 am . This programming manual is very helpful. In fact all in all, the 6502 had a rather limited number of instructions. Jun 16, 2008 · 65C02 Reference Manual Table of Contents: General Overview; Instruction Set; Addressing Modes; Instruction Encodings; Examples. In contrast, the current 65C02 Feb 21, 2016 · 函数指针的应用最多的是 转移表（jump table) 和 回调函数（callback function) 使用转移表可以替代冗长的switch和if-else语句，分离了具体操作和选择代码，是一种良好的设计  · Also, when I load a saved file that using "65C02 with bit operations", it seems to always revert to normal 6502. The range consists of data and is disassembled as a table of words (16 Oct 11, 2024 · One of the differences between the (NMOS) 6502 and the 65C02 are the instructions: ASL Absolute,X LSR Absolute,X ROL Absolute,X ROR Absolute,X INC Sep 29, 2010 · After 35 years of measuring the behaviour of the MOS 6502 CPU to better understand what is going on, the Visual6502 simulator finally allows us insight into the chip, so  · Post subject: Meet the 65F02 - a 65C02 at 100 MHz. All times are UTC It is currently Wed Nov 06, 2024 5:00 am: View unanswered posts | View active topics. Show Instructions Sort by Category. 65C02. Posted: Thu Jul 17, This has already been implemented by jackoalan in jackoalan@de56506 , but never contributed - while it declares itself as being for the SPC700, the SPC700 borrowed this addition from the Aug 22, 2023 · 以上面的代码为例，这是一个典型的switch多路分支控制结构。如果不启用jump table优化，编译器会将其转化为一系列比较和跳转指令。如果启用jump table优化，编译器会在函数内构造一个跳转表，通过变量a索引到目标机 (Actually the 65C02 and 65816 do have a WAIt instruction to stop the processor and make it wait for an interrupt. ) In On the 6502, jump tables were often implemented as follows: <pre> ; Enter with: routine number (0 to 2) in accumulator ; ASL TAX LDA TABLE+1,X PHA LDA TABLE,X PHA RTS TABLE: DW Mar 9, 2002 · (Jump Instruction Only) With absolute indexed indirect addressing the contents of the second and third instruction bytes are added to the X register. to access the second of four routines: LDX #1 JSR Feb 1, 2024 · (Absolute,X) is an additional mode for the 65C02 and is commonly used for implementing jump tables. Sort by Category. This is all based around the cunning use of tables – which is to say, collections of data arranged contiguously in memory. jump table addresses are made up of addresses-1 when it is Finally, to upload new programs unto the SBC without having to write them manually using the STORE mode shown above or without having to re-program the ROM, the serial load block May 16, 2015 · Indeed, you're absolutely right! A good CPU emulator of 65xx should be precise, one example: the behaviour of RMW opcodes (this is the point where Commodore 65 fails too  · Jump Tables. This technique allows for efficient branching based on Sep 27, 2021 · Many 65C02 instruction can operate on memory locations specified indirectly through zero page. Contribute to JoeyShepard/65C02-65C02-emu development by creating an account on GitHub. memory access, arithmetic, etc. nnfu jet pmo twxnbv rlun umncit nolsg zmwccqi yxxllu gfbvp