Testbench

Testbench: 4-way round-robin arbiter

Intermediate

01Objective

Verify priority rotation after each grant and the no-request case. Use self-checking controls and finish with final_report. Perform at least 16 checks with check_output. Your testbench must pass on the correct DUT and detect hidden faults.

02Operation

Inputs: i_reset (1 bit), i_req (4 bits), i_ready (1 bit). Outputs: o_grant (4 bits).

Behavior

Synchronous operations occur on the rising edge of i_clk. Allow signal updates to settle before comparing outputs.
i_reset is active-high and asynchronous; it clears outputs and state unless another value is explicitly specified.
Initial priority 0; search cyclically through 0,1,2,3 from the current pointer. At each edge o_grant identifies at most one request; granting n moves priority to (n+1) modulo 4. With no requests or i_ready=0, o_grant=0000 and the pointer holds.

Chargement…