Picoblaze Enhancements


Board Products  Design Services  Intellectual Property  Design Rescue Seminars Support  Contact  History  News  Careers TechiTips  Partners

We have been doing a lot work on the various variants of PicoBlaze. This small processor family is ideal for small control tasks and it's size means that it can be used many times within a FPGA.  PicoBlaze comes in several variants with different features and different device family targets. Processors are supplied by Xilinx as VHDL netlists which allow some modification by the experienced designer. FPGA variants of PicoBlaze rely on block ram memory for code storage. This local memory has predictable timing which means that you can use software loops for timing function albeit with some care.

Enterpoint can offer customers turnkey solutions based on PicoBlaze  Furthermore we can offer various enhancements in speed, technology crossover of the family members, code paging, block ram sharing and on-the-fly code space modification.

We can speed  up a FPGA based  PicoBlaze in a number of ways depending on your requirements. Typically we can offer a 50 percent increase in clock rate, and mips, over a standard FPGA based PicoBlaze We hope to offer these enhancements as IP cores, or constraints templates,  but as yet they are not well enough documented to put on general sale.

Our technology crossovers offer you the change to choose any PicoBlaze and use it in any Xilinx  device family. We can offer this service in conjunction with speed-ups etc. An example of this where we have taken a Virtex-II PicoBlaze and converted it to the Spartan3/2E/2 technologies. In this case we also modified the core such that it will now run at 122 MHz in a Spartan3 device. We are also expecting to increase this clock rate in a future revision of this crossover.

Some of our  PicoBlaze enhancements are in the memory area. Often the number of block ram memories limits the number of  PicoBlaze cores in a FPGA. We have a number of ingenious mechanisms to share block memories between PicoBlaze's, or to use external memories, or even to use logic fabric as memory. The memory-in -logic conversion is particularly useful to customers in the hand held or battery powered equipment market that are using Spartan XL or Coolrunner devices.

Our on-the-fly code space modification operates in couple of ways. The first method assumes linear code and detects a particular program count value to action a load from an external source to the local block ram. The second mechanism we use operates in conjunction with the running code. In this case the code passes parameters to action and control the loading of code into block ram. If you are interested in this please see our TechiTip on this.

We have planned further product developments for PicoBlaze

If you need to find more general information from the Xilinx website we suggest you start here.

If you are interested in MicroBlaze look here.

A "C" compiler can be found at http://www.poderico.co.uk/index.html. We have not used this compiler ourselves as yet so can not advise on suitability or quality of results from this compiler.

All trademarks acknowledged. Xilinx, PicoBlaze, MicroBlaze, Coolrunner, Spartan, Virtex-II are trademarks of Xilinx Inc.

© Copyright 2003-2009 Enterpoint Ltd. - All rights reserved.