PicoBlaze FAQ – Does PicoBlaze work in Virtex-5?

The simple answer is Yes. The KCPSM3 version of PicoBlaze available from the following web site states it is suitable for Spartan-3 Generation, Virtex-II(PRO) and Virtext-4 devices but it will also work in Virtex-5 devices.

http://www.xilinx.com/products/ipcenter/picoblaze-S3-V2-Pro.htm

So why doesn’t it say it works in Virtex-5?

Well the first simple reason is that I haven’t updated the documentation yet (November 2007). However there is a more technical reason, that being that the fundamental architecture of the Virtex-5 device is different to the supported devices listed. Virtex-5 introduced the 6-input look up table (LUT6) and also has larger Block Memory. My overriding engineering decision when implementing all the PicoBlaze macros has always that they should fit naturally with the device architecture in order that they would be as small as possible. Performance was always a secondary objective, but again working naturally with the architecture really pays dividends when it comes to enhancing the maximum clock speed.

So whilst KCPSM3 works in Virtex-5 it should be recognised that it is not optimised for that architecture and therefore it is somewhat larger and slower than I would like it to be. That said, given the size and performance of Virtex-5 devices it still looks extremely small and fast so I really hope you will still find it acceptable and an efficient way to implement many functions in your Virtex-5 designs.

Regards,

Ken Chapman