Lambdaya-bus

Fpga bus and serialistion for RedPitaya using CλaSH

Installation

• Clash

  Follow installation manuals on clash-lang.org Following this you will install both recent Haskell compiler GHC and Clash compiler

• Install lambdaya-bus and dependencies using cabal

  cabal update
cabal install lambdaya-bus

• Install Xilinx Vivado 2015.4 for example. Tool is free to use and software SDK is not requred.

• Get RedPitaya fpga code.

  Branch clash is patched with code that enables automatic inclusion in existing Redpitaya fpga coe

  git clone -b clash https://github.com/ra1u/RedPitaya.git
  

  or if you have RedPitaya git repo

  cd <git dir>
  git remote add lambdaya https://github.com/ra1u/RedPitaya.git
  git fetch lambdaya
  git checkout -b clash lambdaya/clash
  

Build first core

Example application is available in lambdaya-bus repo and includes code for both core and remote tcp client. It is matrix multiplication core.

Clone repository

git clone https://github.com/ra1u/lambdaya-bus.git
cd lambdaya-bus/examples/MatrixMultiply

compile into verilog code

clash Core.hs --verilog

This will generate verilog folder with with verilog code that can be included in RedPitaya fpga core.

Copy this folder in RedPitaya folder RedPitaya/fpga/rtl/clash

. /opt/Xilinx/Vivado/2015.4/settings64.sh

move to fpga folder

make clean
make fpga

Once finished send fpga bitstream on RedPitaya

ssh root@<RP_IP> tee /dev/xdevcfg < ./out/red_pitaya.bit > /dev/null

That is It. Core is uploaded and running. It represents matrix multiplication of 2 matrices 3x3 with elements being 16 bit Signed values.Addressees for core input are from 0x40500000. Since each value is 16 Bit in wide there are first 9 * 16 bit as first 3x3 matrix and 2nd matrix is from from next bit on. Reading out starts at same address that is 0x40500000. Functions of original core like oscilloscope and function generator are included in bit-stream.

Remote call

Making core and having bus is one part of fun. We can write and read data from fpga using provided monitor tool from address 0x40500000 or we can run this code remotely using haskell and this libraray.

First we need to start server from lambdaya on RedPitaya.

Then set ip in lamndaya-bus/examples/MatrixMultiply/Client.hs for RedPitaya.

ghc -O3 Client.hs

And finaly run client

./Client

to get output

<<1,2,3>,<4,5,6>,<7,8,9>>
<<10,11,12>,<13,14,15>,<16,17,18>>
<<84,90,96>,<201,216,231>,<318,342,366>>

That is 3rd line is product of previous two. What happens here is that 2 matrices are send over tcp on rp server, serialized on fpga bus and consumed by fpga core. Then result is read back same way from core and displayed.