getting value from SV to PY

[aksarup]

I have a read method in PY which calls SV BFM task to read values from a register.

The type of object that gets returned is '_Event'. What method do I need to call to get the register value from this object.

The code is something like this:

 init_bfm = rgy.findObj(r".*\.init_bfm", regex=True)
print("INSIDE READ TASK ADDR => {}".format(addr))
ret_val = await init_bfm.read(addr)
print("INSIDE READ Register ret_val Value => {}".format(ret_val.value))
return ret_val.value

The error I get:
print("INSIDE READ Register ret_val Value => {}".format(ret_val.value))
^^^^^^^^^^^^^
AttributeError: '_Event' object has no attribute 'value'

Any ideas on how values can be passed from SV to PY?

[mballance]

The result yielded by awaiting the call should be the value returned from SV. For example, the DPI 'call_sv_bfm' example contains code like this:

pyhdl-if/examples/call/dpi/call_sv_bfm/call_sv_bfm.py

Lines 26 to 28 in 45d00cc

	await bfm.write(0x8000_0000+(4*i), wr_val)
	rd = await bfm.read(0x8000_0000+(4*i))
	print(f'[Py] readback: {rd}')

The error you are seeing seems familar -- and one that was fixed a while ago. Are you obtaining the pyhdl-if library via pip, or by downloading and installing yourself? Either way, I would recommend ensuring that you have the latest version installed.

[aksarup]

I used pip to install pyhdl-if. I using the latest verion.
How can I confirm that I'm on the latest version?

[mballance]

You can check the version of pyhdl-if using the following command:

% pip show pyhdl-if

You should see output like:

Name: pyhdl-if
Version: 0.0.1.13254700022
Summary: Python interface for HDL programming interfaces
...

If you're using the dpi/call_sv_bfm example as-is, you should check the version of the virtual environment that the script creates:

./example_venv/bin/pip show pyhdl-if

Looking at release dates, you probably want to have a release newer than 0.0.1.12736...

[aksarup]

Thanks, getting the latest verion fixed the dpi example but the cocotb example still has the same issue when running with VCS.