EDN DV document

Goals

DV
- Verify all EDN IP features by running dynamic simulations with a SV/UVM based testbench
- Develop and run all tests based on the testplan below towards closing code and functional coverage on the IP and all of its sub-modules
FPV
- Verify TileLink device protocol compliance with an SVA based testbench

Design features

For detailed information on EDN design features, please see the EDN HWIP technical specification.

Testbench architecture

EDN testbench has been constructed based on the CIP testbench architecture.

Top level testbench is located at hw/ip/edn/dv/tb.sv. It instantiates the EDN DUT module hw/ip/edn/rtl/edn.sv. In addition, it instantiates the following interfaces, connects them to the DUT and sets their handle into uvm_config_db:

Common DV utility components

The following utilities provide generic helper tasks and functions to perform activities that are common across the project:

Global types & methods

All common types and methods defined at the package level can be found in edn_env_pkg. Some of them in use are:

parameter uint MIN_NUM_ENDPOINTS = 1;
parameter uint MAX_NUM_ENDPOINTS = 7;

TL_agent

EDN testbench instantiates (already handled in CIP base env) tl_agent which provides the ability to drive and independently monitor random traffic via TL host interface into EDN device.

Endpoint_agent

EDN testbench instantiates this push_pull_agent(../../../dv/sv/push_pull_agent/README.md) which models an endpoint module.

Csrng_agent

EDN testbench instantiates this agent(../../../dv/sv/csrng_agent/README.md) which models the csrng module.

UVM RAL Model

The EDN RAL model is created with the ralgen FuseSoC generator script automatically when the simulation is at the build stage.

It can be created manually by invoking regtool:

Stimulus strategy

Test sequences

All test sequences reside in hw/ip/edn/dv/env/seq_lib. The edn_base_vseq virtual sequence is extended from cip_base_vseq and serves as a starting point. All test sequences are extended from edn_base_vseq. It provides commonly used handles, variables, functions and tasks that the test sequences can simple use / call. Some of the most commonly used tasks / functions are as follows:

edn_init: Initialize the EDN module from the randomized environment variables in the config.

Functional coverage

To ensure high quality constrained random stimulus, it is necessary to develop a functional coverage model. The following covergroups have been developed to prove that the test intent has been adequately met:

common covergroup for interrupts hw/dv/sv/cip_lib/cip_base_env_cov.sv: Cover interrupt value, interrupt enable, intr_test, interrupt pin

Self-checking strategy

Scoreboard

The edn_scoreboard is primarily used for end to end checking. It creates the following analysis ports to retrieve the data monitored by corresponding interface agents:

tl_a_chan_fifo, tl_d_chan_fifo: These 2 fifos provide transaction items at the end of Tilelink address channel and data channel respectively

Assertions

TLUL assertions: The tb/edn_bind.sv binds the tlul_assert assertions to the IP to ensure TileLink interface protocol compliance.
Unknown checks on DUT outputs: The RTL has assertions to ensure all outputs are initialized to known values after coming out of reset.

Building and running tests

We are using our in-house developed regression tool for building and running our tests and regressions. Please take a look at the link for detailed information on the usage, capabilities, features and known issues. Here’s how to run a smoke test:

$ $REPO_TOP/util/dvsim/dvsim.py $REPO_TOP/hw/ip/edn/dv/edn_sim_cfg.hjson -i edn_smoke