From: Myscha <my...@we...> - 2007-12-24 19:14:29
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Hello, I made a list with some possible SRAMs that I found. Some should do as they are, some require more or less changes at the hardware. Perhaps it will help some people. If you want, you can put in onto the project page for downloading. You must only tell me whom I shall send it. I have one last question before I order the components: Would it make sense to buy a 256k x 32 SRAM? I mean there are two unused pins at the CPLD - perhaps one of them could be used as another address-line to increase the buffer-depth. Could that be easily implemented? Regards, Michael ----- Original Message ----- From: "Jan Smrz" <jan...@vo...> To: <min...@li...> Sent: Sunday, December 23, 2007 9:01 PM Subject: Re: [Minila-forum] Some questions about MiniLA > Hi, > > the important properties are: > - pin compatibility, size, data width (>=32 bits) > - flowthrough mode support > - cycle time < 10ns > - data setup time <= 2ns > - data hold time <= 2ns > > I did not spend too much time with it but your second option > MCM69F737TQ7.5 seems to be usable. > > Jan > > > Myscha napsal(a): >> Hello, >> >> thank you for welcoming me and thanks for the answer. >> >> What SRAM-properties are important? That should mean: which criterias are >> important when choosing a SRAM? >> I found a number of possible replacements, but I'm not sure, whether they >> will do or not. >> >> Regards, >> Michael >> >> >> ----- Original Message ----- >> From: "Jan Smrz" <jan...@vo...> >> To: <min...@li...> >> Sent: Sunday, December 23, 2007 1:01 PM >> Subject: Re: [Minila-forum] Some questions about MiniLA >> >> >> >>> Hello, >>> >>> be welcome. Please see answers below: >>> >>> Myscha napsal(a): >>> >>>> Hello, >>>> >>>> I want to build a MiniLA and I'm searching for the parts therefore. >>>> >>>> Does anyone have parts he doesn't need, especially the PCB (with USB), >>>> the CPLD, the SRAM and the oscillator? >>>> >>>> >>>> And I have some other questions, too: >>>> >>>> 1. Can the XC95288XL be replaced with a XC95144XL? I know this >>>> questions has already been asked, but it was not answered in English. >>>> >>> Unfortunately not, the XC95144 is too small. I tried to make some >>> limited version of miniLA for this device but the limitations were so >>> high that no -144 version of firmware was released. >>> >>>> 2. Is it neccessary to have a pipelined burst SRAM or will one without >>>> pipeline also do? >>>> >>> The pipeline mode is not used. SRAM runs in flowthrough mode. Some >>> people were having problems obtaining the memory and they successfully >>> tried an alternative - IS64LF12832A-7. >>> >>>> 3. What is limiting the speed? The CPLD runs with 200MHz and I >>>> have also seen AS7C33128 with 200MHz. And the sample rate is 100MHz. >>>> >>>> >>> Speed is mainly limited by the CPLD. 200MHz is an ideal situation with >>> very simple (or no) logic implemented. We need 16-bit trigger, 2x >>> 17-bits counters etc. and it slows it down. It was very difficult to >>> make it run at 100MHz. >>> >>>> 4. Are there alternatives for the oscillator? I have no old PC >>>> mainboard where I could take it from. >>>> >>> I don't know, but it has shown up that most 5V oscillators worked at >>> 3.3V too. Try it with standard 5V oscillator, which is not difficult to >>> obtain. >>> >>> >>> Jan >>> >>> > > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Microsoft > Defy all challenges. Microsoft(R) Visual Studio 2005. > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > _______________________________________________ > Minila-forum mailing list > Min...@li... > https://lists.sourceforge.net/lists/listinfo/minila-forum |