ASIC/FPGA Design and Verification Out Source Services

1. First I will start with a few quotes from the LEON user manual, leon2-1.0.30-xst.pdf.
   "The LEON2-XST model includes one optional PCI interface: a simple target-only interface. The interface is developed primarily to support DSU communications over the PCI bus. Focus has been put on small area and robust operation, rather than performance. The interface has no FIFOs, limiting the transfer rate to about 5 Mbyte/s.


2. I will show how I selected to add a FIFO to the design while keeping the unique way of coding style used in the LEON project.


3. The work has been done using the free VHDL simulator namely GHDL. Some of the files of LEON as well as the compilation script had to be changed. The modification are very minor. Moreover I have two scripts for compilation: one is used on my linux machine and one on PC. For the PC I use the dedicated windows GHDL version.


4. I'll explain in the following documents only the modifications, which were done for improving the PCI performance. If someone faces difficulties in compiling LEON with GHDL, I can mail those files, which I modified.


5. The changes to the file leon/ahbmst.vhd, so it supports burst mode, are described in:ahbmst.


6. The changes to the file leon/pci_gr.vhd are explained by using a diff utility (like tkdiff or gvim -d) on the files which can be downloaded from the download area.


7. A word on scripts to compile the design, which I use are at leon GHDL scripts.


8. PCI waveforms examples are at improved PCI waveforms improved PCI waveforms

Home

simualation Control from CPU in SOC

leon GHDL Scripts improved PCI waveforms Download Area