Reg2apb and PASSIVE agent

UVM
,
1

In example code, reg2apb is created only if agent is ACTIVE.

In case I just want to have predictor (passive agent provide info to predictor that keeps register model “aligned” with RTL):

  • do I still need to have reg2apb adapter? I guess yes. Then the code should always create it, not only for PASSIVE configs…
2

In reply to apr:

Predictor is required to convert bus transactions to reg transactions only. So it is fine if bus2reg(apb2reg) adapter is available. So, reg2apb adapter is not required even if a predictor is used along with passive agent to update the reg model.

Provide more details of the example your are referring to, if you still feel otherwise.

3

In reply to S.P.Rajkumar.V:

Here are more detailed analysis:

  1. Lest say I need only PASSIVE environment - RTL is driving apb, and lets say I just want to collect coverage on register fields
  2. Code example shows:
    if(m_cfg.m_apb_agent_cfg.active == UVM_ACTIVE) begin
    reg2apb = reg2apb_adapter::type_id::create(“reg2apb”);
    …
  3. So, due to Point 1, I will use PASSIVE apb agent to monitor apb bus. Due to Point 2, I will not have reg2apb_adapter (that contains predictor, and bus2reg virtual function) => Cannot use passive part of uvm registers for register shadow model and coverage…

So this shows that we should create adapter regardless if apb agent is PASSIVE or ACTIVE, correct?

4

In reply to apr:

In reply to S.P.Rajkumar.V:
…
So this shows that we should create adapter regardless if apb agent is PASSIVE or ACTIVE, correct?

Yes, you should create a ‘reg2apb_adapter’ in both cases.

5

In reply to Dmitrii:
So example from Cookbook should be changed to take adapter in PASSIVE also…
Current code:

function void spi_env::connect_phase(uvm_phase phase);
  if(m_cfg.m_apb_agent_cfg.active == UVM_ACTIVE) begin
    reg2apb = reg2apb_adapter::type_id::create("reg2apb");
    //
    // Register sequencer layering part:
    //
    // Only set up register sequencer layering if the top level env
    if(m_cfg.spi_rm.get_parent() == null) begin
      m_cfg.spi_rm.APB_map.set_sequencer(m_apb_agent.m_sequencer, reg2apb);
    end
  end
endfunction: connect_phase

We should not have that IF in order to create adapter, correct?