class axi_s_monitor extends uvm_monitor;
    `uvm_component_utils(axi_s_monitor)

    // Components
    uvm_analysis_port#(axi_transaction#(D_WIDTH, A_WIDTH)) ap;
    virtual axi_intf#(.D_WIDTH(D_WIDTH), .A_WIDTH(A_WIDTH)).SMON vif;
    // variables
    axi_transaction#(D_WIDTH, A_WIDTH) w_trans, r_trans;
    bit w_done, r_done;
    int b_size;
    
    // Methods
    extern task run_mon(uvm_phase phase);
    extern task write_monitor();
    extern task read_monitor();

    function new(string name, uvm_component parent);
        super.new(name, parent);
        w_done = 1;
        r_done = 1;
    endfunction //new()

    //  Function: build_phase
    extern function void build_phase(uvm_phase phase);
    
    //  Function: run_phase
    extern task run_phase(uvm_phase phase);
    
endclass //axi_s_monitor extends uvm_monitor

function void axi_s_monitor::build_phase(uvm_phase phase);
    ap = new("ap", this);
endfunction: build_phase

task axi_s_monitor::run_phase(uvm_phase phase);
    forever begin
        run_mon(phase);
        @(vif.mon_cb);
    end
endtask: run_phase

task axi_s_monitor::run_mon(uvm_phase phase);
    fork
        if(w_done) begin
            phase.raise_objection(this);
            w_done = 0;
            write_monitor();
            w_done = 1;
            phase.drop_objection(this);
        end
        if(r_done) begin
            phase.raise_objection(this);
            r_done = 0;
            read_monitor();
            r_done = 1;
            phase.drop_objection(this);
        end
        
    join_none
endtask: run_mon

task axi_s_monitor::write_monitor();
    if(vif.mon_cb.AWVALID && vif.mon_cb.AWREADY) begin
        w_trans         = axi_transaction#(D_WIDTH, A_WIDTH)::type_id::create("w_trans");
        w_trans.addr    = vif.mon_cb.AWADDR;
        w_trans.id      = vif.mon_cb.AWID;
        w_trans.b_size  = vif.mon_cb.AWSIZE;
        w_trans.b_len   = vif.mon_cb.AWLEN;
        w_trans.b_type  = B_TYPE'(vif.mon_cb.AWBURST);
        w_trans.data    = new [w_trans.b_len+1];
        for (int i=0; i<w_trans.b_len+1; i++) begin
            @(vif.mon_cb);
            wait(vif.mon_cb.WVALID && vif.mon_cb.WREADY);
            w_trans.data[i] = new [D_WIDTH/8];
            for (int j=0; j<D_WIDTH/8; j++) begin
                w_trans.data[i][j] = vif.mon_cb.WDATA[8*j+:8];
            end
        end
        wait(vif.mon_cb.BVALID);
        w_trans.b_resp = vif.mon_cb.BRESP;
        ap.write(w_trans);
        `uvm_info("SMON", $sformatf("WTRANS %s", w_trans.convert2string()), UVM_HIGH)
    end
endtask: write_monitor

task axi_s_monitor::read_monitor();
    if(vif.mon_cb.ARVALID && vif.mon_cb.ARREADY) begin
        r_trans         = axi_transaction#(D_WIDTH, A_WIDTH)::type_id::create("r_trans");
        r_trans.addr    = vif.mon_cb.ARADDR;
        r_trans.id      = vif.mon_cb.ARID;
        r_trans.b_size  = vif.mon_cb.ARSIZE;
        r_trans.b_len   = vif.mon_cb.ARLEN;
        r_trans.b_type  = B_TYPE'(vif.mon_cb.ARBURST);
        r_trans.data    = new [r_trans.b_len+1];
        r_trans.r_resp  = new [r_trans.b_len+1];
        for (int i=0; i<r_trans.b_len+1; i++) begin
            @(vif.mon_cb);
            wait(vif.mon_cb.RVALID && vif.mon_cb.RREADY);
            r_trans.data[i] = new [D_WIDTH/8];
            for (int j=0; j<D_WIDTH/8; j++) begin
                r_trans.data[i][j] = vif.mon_cb.RDATA[8*j+:8];
            end
            r_trans.r_resp[i] = vif.mon_cb.RRESP;
        end
        ap.write(r_trans);
        `uvm_info("SMON", $sformatf("RTRANS %s", r_trans.convert2string()), UVM_HIGH)
    end
endtask: read_monitor