Transaction Reconstruction: Temporal Decode to Objects

Stateful decode

Most protocols require partial capture across cycles. Use explicit monitor states and only publish once semantic completion is reached.

[MON] reconstruction states
IDLE -> CAPTURE -> COMPLETE
reset/abort returns to IDLE without publish

typedef enum {MON_IDLE, MON_CAP} mon_state_e;
mon_state_e st;
my_txn pending;

task run_phase(uvm_phase phase);
  forever begin
    @(posedge vif.clk);
    if (!vif.rst_n) begin st = MON_IDLE; pending = null; continue; end
    // collect and finalize pending transaction
  end
endtask

• One semantic transfer should map to one published transaction.

• Clear pending objects on reset and abort paths.

• Normalize fields before publication for consistency.

Applied Patterns

This appendix consolidates reusable monitor patterns for enterprise-scale UVM environments where multiple teams share protocol VIP.

Use this as a quick implementation checklist before releasing monitor updates into regression branches.

[MON][UVM][AGT] reusable pattern grid

sampling:
  accepted-handshake gating only

reconstruction:
  key-based accumulator with completion predicate

publishing:
  clone policy + counter instrumentation

debug:
  boundary-first triage with deterministic smoke

function void monitor_health_report();
  `uvm_info("MON_HEALTH",
    $sformatf("sampled=%0d published=%0d dropped=%0d pending=%0d",
      sampled_cnt, published_cnt, dropped_cnt, pending_cnt),
    UVM_LOW)
endfunction

[MON] review checklist

- passive contract verified
- reset/flush policy documented
- publish ownership policy documented
- consumer fan-out validated
- counters visible in report_phase

• Design monitor updates as API changes to downstream consumers, not local edits.

• Keep monitor diagnostics always-on and low overhead for regression reliability.

• Revalidate sample-to-publish boundary after every protocol extension.