logic_vector_mvb environment

This environment convert logic_vector transaction to mvb transactions.

The environment is configured by these four parameters: For more information see mvb documentation.

• ITEMS

• ITEMS_WIDTH

Top sequencers and sequences

In the RX direction, there is one sequencer that generates logic_vector transactions. The generated transactions will be randomly ordered and then converted to MVB transactions.

In the TX direction, there is one sequencer of type mvb::sequencer #() which generates the DST_RDY signal.

Both environments send logic_vector transactions through the analysis_export.

Configuration

The config class has three variables.

Variable	Description
active	Set to UVM_ACTIVE if the agent is active, otherwise set it to UVM_PASSIVE.
interface_name	The name of the interface under which you can find it in uvm config database.
seq_cfg	Configure a low-level sequence that converts logic_vector to MVB words.

The top level environment contains the reset_sync class, which is required for reset synchronization. The example shows how to connect the reset to the logic_vector_array_mfb environment and its basic configuration.

class test extends uvm_test
    `uvm_componet_utils(test::base)
    reset::agent                m_resets;
    logic_vector_mvb::env_rx#(...) m_env;

    function new(string name, uvm_component parent = null);
        super.new(name, parent);
    endfunction

    function void build_phase(uvm_phase phase);
         logic_vector_mvb::config_item m_cfg;

         m_resets = reset::agent::type_id::create("m_reset", this);

         m_cfg = new();
         m_cfg.active = UVM_ACTIVE;
         m_cfg.interface_name = "MFB_IF";
         m_cfg.meta_behav     = config_item::META_SOF;
         m_cfg.cfg = new();
         m_cfg.cfg.space_size_set(128, 1024);
         uvm_config_db#(logic_vector_mvb_env::config_item)::set(this, "m_eth", "m_config", m_cfg);
         m_env = logic_vector_mvb::env_rx#(...)::type_id::create("m_env", this);
    endfunction

     function void connect_phase(uvm_phase phase);
        m_reset.sync_connect(m_env.reset_sync);
     endfunction
endclass

Low sequence configuration

The configuration object config_sequence contains one function.

Variable	Type	Description
space_size_set(min, max)	[bytes]	Set min and max space between two logic_vector items in a MVB transaction.

RX Inner sequences

For the RX direction, there is one basic sequence class called “sequence_simple_rx_base”, which simplifies creating other sequences. It processes the reset signal and exports the create_sequence_item virtual function. In this function, a child can create a mvb::sequence_item as they like.

The environment has three sequences. The table below describes them. In the default state, the RX env runs sequence_lib_rx.

Sequence	Description
sequence_rand_rx	A basic random sequence. This sequence behaves very variably.
sequence_burst_rx	The sequence sends data in bursts.
sequence_full_speed_rx	The sequence gets data and then sends them as quickly as possible.
sequence_stop_rx	This sequence doesn’t send any data. There are no data on the interface.
sequence_lib_rx	Repetitively Randomly choose one of the sequences above and run it.

The example below shows how to change the inner sequence to test the maximum throughput. The environment runs the sequence_full_speed_rx sequence instead of the sequence_lib_rx.

class mvb_rx_speed#(...) extends logic_vector_mvb_env::sequence_lib_rx#(...);

    function new(string name = "mvb_rx_speed");
        super.new(name);
        init_sequence_library();
    endfunction

    virtual function void init_sequence(config_sequence param_cfg = null);
        if (param_cfg == null) begin
            this.cfg = new();
        end else begin
            this.cfg = param_cfg;
        end
        this.add_sequence(logic_vector_mvb_env::sequence_full_speed_rx #(REGIONS, REGION_SIZE, BLOCK_SIZE, ITEM_WIDTH, META_WIDTH)::get_type());
    endfunction
endclass


class test extends uvm_test
    `uvm_componet_utils(test::base)
    logic_vector_mvb::env_rx#(...) m_env;

    function new(string name, uvm_component parent = null);
        super.new(name, parent);
    endfunction

    function void build_phase(uvm_phase phase);
        ...
         logic_vector_mvb_env::sequence_lib_rx#(...)::type_id::set_inst_override(mvb_rx_speed#(...)::get_type(),
         {this.get_full_name(), ".m_env.*"});
         m_env = logic_vector_mvb::env_rx#(...)::type_id::create("m_env", this);
    endfunction
endclass