I would like to build an universal measurement device, composed of a frequency meter and a bus protocol analyser (among other things). It will be based on a Spartan 3 chip, i.e. XC3S200-4TQ144C, which is the largest S3 device I can buy in very small quantities without problems (with Cyclone 2 the situation is much worse... :-( ). I have never used Xilinx parts before, so could you please answer the following, perhaps trivial, questions?
- What is the highest frequency I can measure using that part a) without any tricks; b) with some tricks -- I know that Peter Alfke has implemented a freqency meter capable of 450MHz on an S2(?). :-)
- Is it possible to obtain some information about the bitstream format of that particular chip? The device should support all the IO modes that Spartans support, which implies about 30 different configuration files... However, I believe that the only thing that needs different configuration settings is the IOB subsystem, since the rest of the device remains unchanged. So I would like to dynamically patch the bitstream by an on-board microcontroller, which will generate an appropriate stream from a single configuration file template. But where is the IO configuration part of the stream and how is it encoded? Note: I don't want any warranties etc. from Xilinx and I know that the format could be changed in the future, but I am only interested in the format of the chip I hold in my hand.
Best regards Piotr Wyderski