title: “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

Current status

  • [Design & verification stage]({{< relref “hw” >}})
    • [HW development stages]({{< relref “doc/project/development_stages” >}})
  • Simulation results

Design features

For detailed information on EDN design features, please see the [EDN HWIP technical specification]({{< relref “..” >}}).

Testbench architecture

EDN testbench has been constructed based on the [CIP testbench architecture]({{< relref “hw/dv/sv/cip_lib/doc” >}}).

Block diagram

Block diagram

Top level testbench

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:

  • [Clock and reset interface]({{< relref “hw/dv/sv/common_ifs” >}})
  • [TileLink host interface]({{< relref “hw/dv/sv/tl_agent/README.md” >}})
  • EDN IOs
  • Interrupts ([pins_if]({{< relref “hw/dv/sv/common_ifs” >}})
  • Alerts ([pins_if]({{< relref “hw/dv/sv/common_ifs” >}})
  • Devmode ([pins_if]({{< relref “hw/dv/sv/common_ifs” >}})

Common DV utility components

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

  • [common_ifs]({{< relref “hw/dv/sv/common_ifs” >}})
  • [dv_utils_pkg]({{< relref “hw/dv/sv/dv_utils/README.md” >}})
  • [csr_utils_pkg]({{< relref “hw/dv/sv/csr_utils/README.md” >}})

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:


### TL_agent
EDN testbench instantiates (already handled in CIP base env) [tl_agent]({{< relref "hw/dv/sv/tl_agent/README.md" >}})
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({{< relref "hw/dv/sv/push_pull_agent/README.md" >}}) which models an endpoint module.

###  Csrng_agent
EDN testbench instantiates this agent({{< relref "hw/dv/sv/csrng_agent/README.md" >}}) which models the csrng module.

### UVM RAL Model
The EDN RAL model is created with the [`ralgen`]({{< relref "hw/dv/tools/ralgen/README.md" >}}) FuseSoC generator script automatically when the simulation is at the build stage.

It can be created manually by invoking [`regtool`]({{< relref "util/reggen/README.md" >}}):

### 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
<!-- * analysis port1:
* analysis port2:
explain inputs monitored, flow of data and outputs checked -->

#### Assertions
* TLUL assertions: The `tb/edn_bind.sv` binds the `tlul_assert` [assertions]({{< relref "hw/ip/tlul/doc/TlulProtocolChecker.md" >}}) 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]({{< relref "hw/dv/tools/README.md" >}}) 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:
```console
$ $REPO_TOP/util/dvsim/dvsim.py $REPO_TOP/hw/ip/edn/dv/edn_sim_cfg.hjson -i edn_smoke

Testplan
{{< incGenFromIpDesc “../../data/edn_testplan.hjson” “testplan” >}}