IRAM Verification

1
IRAM Verification

• Sam Williams
• IRAM Summer Retreat 2000

2
Tools Overview

• vsim-isa(,-sync) ? vsim
• rand_gen / rand2sc
• verify (includes interface to all simulators, asm
  programs, random test generator, c interface for
  generating code/data, init/test operations, etc)
• Tools from MIPS for running their test suites
• vsim-p is no longer used

3
Verify Script Overview

• .test file format has the following sections
• init initialize any variable
• code contains assembly language test
• c contains c program whose output is
  appended to the assembly
• test contains the registers/memory and
  values to compare against, included in FP
  compares is a tolerance
• config high level script configuration
• verify can also run random regressions and
  generate n distinct fails
• sync simulation is necessary to ensure coherency
  in program code. only needs to be run once.

4
Testsuites

• MIPS Core testsuite (150 tests, provided only a
  subset of the 60 modes, for a total of about 1600
  test/mode combinations)
• FPU testsuite (also from MIPS) (another 150
  tests, only 300 test/mode combinations)
• Vector testsuite (gt500 tests, including tests for
  individual instructions, chaining, vld/vst
  hardware specifics, and complex operations. All
  self-checking)
• Random tests (take few seconds to generate, can
  run about 3000/day)

5
Status

• All tests in the MIPS test suite have been run on
  the core they provided with their simulation
  environment, as well as cache and mmu tests
• All the vector tests have been run on the old isa
  simulator (1 outstanding fail).
• Cant include FPU tests in regression until we
  get stuff from IBM

6
Status (continued)

• New vsim, designed to suit or needs, was released
  last Friday.
• there are only a couple of tests from the
  testsuite which still fail.
• Some tests had to be modified once the simulator
  was fixed so that it matches hardware.
• Complete RTL is almost ready to be put together
  and simulated.

7
Future Work

• Complete move to new vsim
• Add hooks to RTL for simulation
• Simulate RTL and netlist
• Evaluate and run coverage tool