Yet Another Simple Router - a COCOTB verification example of the Verilog RTL simple router model. Feel free to use this to kickstart your verification environment.
This is a work in progress.
Requirements:
| Package | Usage |
|---|---|
| cocotb | writing testbenches in Python |
| cocotb-coverage | functional coverage definitions, gathering and metrics |
| cocotb-test | Optional for running testcases using pytest framework. Makefiles are provided as an alternative |
| pytest | Optional for running testcases together with cocotb-test |
| iverilog | Free digital hardware simulator (or use any commercial one) |
Running examples:
Folder tests contain an example of how to run your testcases using pytest framework. Cocotb-test and pytest packages are used for that.
cd tests + pytest or pytest <test_name> to run all or just a specific test / set of tests. Refer to pytest documentation on how to select tests to run.
Alternatively there are makefiles provided:
cd tb/config_regs + make to run with default arguments.
You can also provide additional args like this: make SIM=questa SIM_ARGS="+FOO +BAR=5". SIM (simulator) supports e.g. icarus, questa, vcs, xcelium. You can use SIM_ARGS to pass additional arguments, in this example FOO is set to 1 (+FOO == +FOO=1) and BAR is set to 5. Take a look at testcases and ArgParser from tb_common on how to define and use these arguments in your testbenches.
Initial Router Specification:
1x3 Router
1 input channel
3 output channels
1 clock clk
active low async reset rst_n
Data_in data [7:0]
Data_in_req data_req
Data_ack data_ack
Same IF for output
Minimal Register interface
Packet format [header / size / data / CRC], header first
HEADER MSB [HEADER|SIZE] LSB :
2b (address), 6b payload size (bytes)
1-63bytes data (size+1, pkts have a minimum of 1 byte of data, does not include CRC byte)
8bit CRC (calculated over everything)
Bad address or CRC - packet discarded
Channel addresses configurable via registers
Multiple channels can have the same address
Config
Simple interface for programming (addr, data, enable)
Each channel has configurable address (1) via registers
CRC check on / off