How to get the read signals in the sequence from driver in pipeline style UVM? - system-verilog

Question

I'm trying to get read data (HRDATA) from a driver in the sequence or test.
This is my driver:
////////// Pipelined UVM Driver //////////
class ahb_pipelined_driver extends uvm_driver #(ahb_seq_item);
`uvm_component_utils(ahb_pipelined_driver)
/// Virtual Interface
virtual ahb_interface ahb_if;
/// Constructor
....
function void build_phase(uvm_phase phase);
super.build_phase(phase);
...
endfunction
forever begin
ahb_if.HADDR <= req.HADDR;
ahb_if.HWRITE <= req.HWRITE;
ahb_if.HBURST <= req.HBURST;
req.HRDATA = ahb_if.HRDATA;
req.HRESP = ahb_if.HRESP;
ahb_if.HWDATA <= req.HWDATA;
end
// Return the Request as Response
seq_item_port.put(req);
end_tr(req);
end
endtask:
endclass:
I read the read data from req.HRDATA = ahb_if.HRDATA; in the driver, and I can check the value.
But, the problem is that I'd like to send read data to the sequence but this sequence immediately finished after I call seq_item_port.get() in the driver. So I can’t both wait for the read data to be available and have pipelined operation.
I want to send the read data to the sequence or test from the driver. How am I supposed to do that?

Answer 1

You are not following the recommended UVM approach.
The driver should not sample the "read" data and check it. You should create a UVM agent with a driver and a monitor. The monitor should sample the read data and send it to a scoreboard for checking.
I recommend that you change your driver such that it no longer tries to sample the read data. Then create a UVM monitor which collects all AHB transactions (reads and writes) and sends them to a scoreboard.
See also:
Basic UVM example
UVM AHB example on EDA Playground