Simulation Config File

Simulation config files are used to define the files needed for a simulation as well as define the tests that can be run. Each variant will have one and only one simulation config file.

Required Entries

PROJ_ROOT

This item describes where the project root is located relative to the directory containing the config file. For instance, if a directory structure was setup to look like the following:

.
|-- rtl
|   |-- and_nand.v
|   `-- or_nor.v
`-- test
    |-- variant0
    |   |-- tb.v
    |   `-- v.cfg
    `-- variant1
        |-- tb.v
        `-- v.cfg

The root of the project is at the top of the tree and the two config files, v.cfg, are two directories down, so relative to those config files PROJ_ROOT would be two directories up or ../../

PROJ_ROOT = ../../

RTL_FILES

This item is a list of all the RTL files needed by the variant. All files are relative to the PROJ_ROOT.

RTL_FILES = rtl/and_nand.v rtl/or_nor.v

RTL_INC_DIRS

If there are files include in the source via the `include statement the compiler needs to know where those files are located and RTL_INC_DIRS defines those directories.

RTL_INC_DIRS = rtl/includes

TEST_FILES

Any files used by the testbench that aren’t RTL are defined here.

TEST_FILES = test/tb.v test/other_test_file.v

TEST_INC_DIRS

Just like the RTL_INC_DIRS, if there are included files used by the testbench the directories they are contained in would be defined here.

TEST_INC_DIRS = test/includes test/models/includes

Optional Entries

DEFINES

DEFINES = VERBOSE FILTEN

TIMEOUT

TIMEOUT = 50000000

TIMESCALE

TIMESCALE = 1ns/10ps

Todo

Define the rest of the optional entries

Here are all of the available options and their default values:

'BUILDDIR':         'simbuild',
'SIMFILE':          'sim',
'LOGFILE':          'sim.log',
'BUILDFILE':        'build.log',
'PROJ_ROOT':        './',
'DEFINES':          '',
'PLUSARGS':         '',
'RTL_FILES':        '',
'RTL_INC_DIRS':     '',
'TEST_FILES':       '',
'TEST_INC_DIRS':    '',
'TASKS':            '',
    # Auto Test Variables
'AUTO_TEST_FILE':   'auto_test.v',
'DUMPFILE':         'out.vcd',
'DUMPVARS':         '(0,tb)',
'TIMESCALE':        '1ns / 10ps',
'TIMEOUT':          '40000000',
'RESET':            '',
'FINISH':           '$finish',
'TIMEOUT_ERROR':    '',
    # Simulator Specific Options
'COMPCMD':          'iverilog',
'SIMCMD':           'vvp',
'WARN':             'all',

Declaring Tests

Tests are simple collections of Verilog tasks. Any task that you have defined in your testbench can be run from a test. Declaring a test with a single tasks would look like the following.

[basic_test]
TASKS = tb.basic

Tests can have more than one task too.

[regression]
TASKS = tb.basic
        tb.set_rate(1)
        tb.send_data
        tb.set_rate(3)
        tb.send_data

Tests can also call other tests.

[basic1]
TASKS = tb.basic1

[basic2]
TASKS = tb.basic2

[basic3]
TASKS = tb.basic3

[regression]
TASKS = [basic1] [basic2] [basic3]

Only 1 level of recursion is currently allowed.

Example

Here’s a full configuration file named v.cfg that defines the required entries as well as some optional entries and defines some tests.

[DEFAULT]
PROJ_ROOT = ../../

RTL_FILES = rtl/and_nand.v
            rtl/or_nor.v

DUMPVARS = (0,tb)

TEST_FILES =    test/variant0/tb.v

TEST_INC_DIRS = test/variant0/

[basic1]
TASKS = tb.basic1

[basic2]
TASKS = tb.basic2

[basic3]
TASKS = tb.basic3

[regression]
TASKS = [basic1] [basic2] [basic3]

Listing available tests with SimShop:

$ shop -l
Found the following config files
--------------------------------
./v.cfg

./
    basic1
    basic2
    basic3
    regression

To run a simulation:
shop <path_to/variant>/<test>

Example:
    shop regression

Running the regression test.

$ shop regression

Verifying target...
  PATH    : ./
  VARIANT : variant0
  TEST    : regression


Generating auto test file based on test 'regression'

Removing old build directory: simbuild/regression

Making new build directory: simbuild/regression

iverilog -Wall -osimbuild/regression/sim -I../../test/variant0/ ../../test/variant0/tb.v ../../rtl/and_nand.v ../../rtl/or_nor.v simbuild/regression/auto_test.v
vvp -n -lsimbuild/regression/sim.log simbuild/regression/sim

<0> Dump file set to simbuild/regression/out.vcd.
<0> Dumping has been turned OFF. Nothing will be dumped.

<0> Starting Auto Tests
Task: basic1
Task: basic2
Task: basic3


Simulation Score
`-- variant0
    `-- regression              [PASS]  (00h 00m 00s)

Passed      1/1 (100.0%)
Failed      0/1 (0.0%)
Invalid     0
Incomplete  0
Not Run     0
Errors      0
Warnings    0
Run Time    00h 00m 00s