Plasma - most MIPS I(TM) opcodes

Hi

I have been trying to compile, synthesize, and load the Plasma CPU onto a Spartan 3 board with little success. I keep getting this XST error:

WARNING:Xst:2254 - Area constraint could not be met for block <plasma_if>, final ratio is 112.

Exactly what files should be used to get just the basic CPU running on the FPGA with the ability to talk over the serial cable?

Thanks

Which Spartan 3 board are you using? The multiplication block is the largest block. I recommend editing mlite_cpu.vhd and commenting out the call to mult and replace it with: c_mult<=ZERO; pause_mult<='0'; You can then use software based multiplication and division. See kernel/makefile for flags needed when compiling C code.

At a minimum you will need the following VHDL files:

mlite_pack.vhd, alu.vhd, bus_mux.vhd, control.vhd, mem_ctrl.vhd, mlite_cpu.vhd, pc_next.vhd, plasma.vhd, ram_image.vhd (created from ram_xilinx.vhd), reg_bank.vhd shifter.vhd uart.vhd plasma_if.vhd

Steve Rhoads rhoadss@yahoo.com

Thanks for the response. I am using the 3s200ft256 -4 Spartan 3 from Digilent. I'm also assuming plasma_if.vhd should be the top level unit? I am using Active HDL and Xilinx Webpack 10.1. I set plasma_if.vhd as the top level. Do I need to tweak any of the synthesis settings? With the files listed can I load different programs I write after creating the ram_image.vhd and run them on the FPGA seeing the results via the serial interface? I am trying to get the lab3-1 listed on this website to run for a class in embedded systems programming I am teaching this fall: http://www.lirmm.fr/~marchesan/index.php?section=lectures&lec=1

Thanks

John

I agree with your statements. Place bootldr into ram_image.vhd to be able to download other programs.

Finally got it to work, thanks, now all I need to do is figure how to make my C programs work without the multiplier unit

Finally got it to work, thanks, now all I need to do is figure how to make my C programs work without the multiplier unit

Everything works fine, thanks for your help