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Hi Josh, I'd be interested to see your paper when you are finished. The Leon looks nice ... but I don't have a 800K gate Virtex FPGA to play with. I'm using the BurchED FPGA board with the XC2S200. Are there any small 32 bit CPUs that will fit in a 200K gate FPGA ? I was wondering about the transputer (T425). Are there any copyrights on the Transputer instruction set ? I can't find much on the transputer instruction set on the web, although I have not done an exhaustive search as yet. The google search did turn up a newsgroup post on FPGACPU regarding the transputer I beleive the transputer is stack based and only has 3 x 32 bit registers so should be fairly small. The other possibility is to design my own 32 bit CPU, but then I'd have to design a tool set for it too. John Kent. Josh Pfrimmer wrote: >Oooh... good topic for me (and in light of recent list politics, I sure hope >it's interesting to some of you as well :) ) > >I'll be writing a paper in the next few weeks: a survey of commercially and >freely available 32-bit RISC IP cores. > >For the paper, I'm interested in hard and soft cores, but for the future, my >research will require one that I can customize (that is, VHDL or Verilog >available). I'm already looking at LEON for that... but I'd appreciate >input as well. > >Thanks > >Josh Pfrimmer, B.Eng > -- http://members.optushome.com.au/jekent |
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Transputers [ was What are peoples opinion of the Altera Nios Processor? ]
Started by ●March 19, 2003
Reply by ●March 19, 20032003-03-19
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John Kent wrote: > Hi Josh, > > I'd be interested to see your paper when you are finished. > The Leon looks nice ... but I don't have a 800K gate Virtex FPGA > to play with. I'm using the BurchED FPGA board with the XC2S200. > Are there any small 32 bit CPUs that will fit in a 200K gate FPGA ? If you mean a cpu with built in cache and MMU and advanced features, no If you mean a Classic RISC machine at say 8 Mhz ** then yes you can. Remember the wealth of ideas here, http://www.fpgacpu.org/index.html Ben. ** ballpark guess of the speed. |
Reply by ●March 19, 20032003-03-19
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Hi Ben ... yes 8 MHz is fine ... I'll have a further poke around. I thought the standard Risc architecture had a register file of 32 x 32 bit registers, which makes for a largish machine. If I want MMU and cache I can go out and buy a commercial chip for a lot less money and bother :-) I had visions of designing a stripped down 68K with 4 x 32 bit data registers and 4 x 32 bit address registers and the basic 6800 dual operand instructions branches, jumps and a stack. But I'd have to write a compiler and assembler to suit. I'd like something I can run a MSDOS file system out of a Compact Flash module. John. ben franchuk wrote > >If you mean a cpu with built in cache and MMU and advanced features, no >If you mean a Classic RISC machine at say 8 Mhz ** then yes you can. >Remember the wealth of ideas here, http://www.fpgacpu.org/index.html >Ben. >** ballpark guess of the speed. > -- http://members.optushome.com.au/jekent |
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Reply by ●March 19, 20032003-03-19
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John Kent wrote: > Hi Ben ... > > yes 8 MHz is fine ... I'll have a further poke around. > I thought the standard Risc architecture had a register file > of 32 x 32 bit registers, which makes for a largish machine. > If I want MMU and cache I can go out and buy a commercial > chip for a lot less money and bother :-) Here is a good text on computer architecture. http://www.rdrop.com/~cary/html/computer_architecture.html#misc > I had visions of designing a stripped down 68K with 4 x 32 bit data > registers > and 4 x 32 bit address registers and the basic 6800 dual operand > instructions > branches, jumps and a stack. But I'd have to write a compiler and assembler > to suit. Well you have to write them anyhow.Several cross-assemblers are table driven so creating a assembler is not that hard, providing you have a C-compiler. The hardest part of designing a instruction set is keeping it simple clean and fast.The physical aspects of hardware need to be kept in mind while designing but hardware is only a small part of the system. The total system and type of problems to be solved are also a factor. > I'd like something I can run a MSDOS file system out of a Compact Flash > module. Almost any cpu would work for that and , Gasp! you could even use a crummy intel 8086 chip for that. :) > John. Ben. |
Reply by ●March 20, 20032003-03-20
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>I'd like something I can run a MSDOS file system out of a Compact Flash >module. Do you mean you want to run DOS on the processor proper? If so, then you have to have x86 compatibility, and you might as well use a 386. If, on the other hand, you mean you want to access a MSDOS file system from a non x86 processor, that's a different story. It's just a question of using the FAT file system. For that, I'd recommend having a look at the FAT file system spec. Note that for smaller compact flash, you only need the FAT12 system, but for larger (>64MB, I think, but it might be 128) you'll need FAT16. --Brendan |
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Reply by ●March 20, 20032003-03-20
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I Agree with you might as well use a 386... To have a uP sys that can run linux or dos, the cost of: Hardware design and debug time of uP sys logic resources overal developement time I.E. Increased simulation, synthesis, Translate-Map-P&R times. Your better off designing in a dirt cheap 486, single chip computer... one having UARTS, USB ( with cold boot from usb option, for faster developement ) Just be careful who's IC you design in.. With this exact scenario I have been burned, as we designed in a micro that had just been scheduled for obsoletion... The company had alot of stock on the distributors shelves and they went out of business.. We probobly spent the money we saved initially, when we re-turned the design & PCB to accomodate another uP. Moose --------------------------------- |
