Overview

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mMips in MyHDL

This mMips in MyHDL is used in course 5JJ55 on TU/e. Few implementation variants are available now:

  1. A single cycle mini-mini MIPS
  2. A pipelined, multicycle mini MIPS

You can simulate the mMips and generate VHDL and/or Verilog.

Prerequisites: python with MyHDL

Single Cycle Mini-mini MIPS

Typical usage:

#!/usr/bin/env python from myhdl import * from single_cycle_mmmips.sc_mmmips import sc_mmmips

if __name__ == "__main__":

clk = Signal(bool(0)) mips_inst = toVerilog(sc_mmmips, clk) print "sc_mmmips generated"

def testbench():

clk = Signal(bool(0)) halfPeriod = delay(5)

@always(halfPeriod) def driveClk():

clk.next = not clk if clk:

print "Time:", now()

i_mips = sc_mmmips(clk)

return instances()

# Initialization (automatically done, now, with default filenames) # Files could be specified at instantiation, if needed #i_pmem.init("mips_rom.bin"); #i_dmem.init("mips_ram.bin");

tb = traceSignals(testbench) sim = Simulation(tb) sim.run(200)

return

A synthesizable Mini MIPS

Typical usage often looks like this:

#!/usr/bin/env python

from mmips.testbench import testbench

if __name__ == "__main__":

clk = Signal(bool(0)) rst = Signal(bool(0)) enable = Signal(bool(1)) # Enable the system period = 10 # clock period in ns

def main():

tb = testbench(clk, enable, rst)

@The Instance def clkgen():

yield delay(period // 2) clk.next = not clk

@always(clk.posedge) def stop():

if now() > 2300:
print now() raise StopSimulation

return instances()

tb = traceSignals(main) sim = Simulation(tb) sim.run()

veri = toVerilog(testbench, clk, enable, rst) print "testbench generated in verilog"

vhdl = toVHDL(testbench, clk, enable, rst) print "testbench generated in VHDL"

Before running a simulation the memory of the processor needs to be initialized with code and data. For now a binary file named "mips_mem.bin" needs to be present in the run directory.

Compiler

Compiler and disassembler are available from TU/e http://www.es.ele.tue.nl/education/5JJ55-65. You need 'lcc' to generate binary images to enable simulation.

Contributors

S.Stuijk and A.S.Slusarczyk for producing the original SystemC model for the TU/e course 5JJ55-65 http://www.es.ele.tue.nl/education/5JJ55-65.

Thanks also to

Jan Decaluwe, for creating MyHDL http://www.myhdl.org.