diff --git a/axi_tb_top.sv b/axi_tb_top.sv
new file mode 100644
index 0000000..433e3ad
--- /dev/null
+++ b/axi_tb_top.sv
@@ -0,0 +1,42 @@
+// `include "uvm_pkg.sv"
+import uvm_pkg::*;
+`include "uvm_macros.svh"
+`include "axi_config_objs.svh"
+`include "axi_interface.sv"
+`include "axi_transaction.sv"
+`include "axi_write_seq.sv"
+`include "axi_read_seq.sv"
+`include "axi_m_driver.sv"
+`include "axi_m_monitor.sv"
+`include "axi_master_agent.sv"
+`include "axi_s_driver.sv"
+`include "axi_s_monitor.sv"
+`include "axi_slave_agent.sv"
+`include "axi_scoreboard.sv"
+`include "axi_env.sv"
+`include "axi_test.sv"
+`include "uvm_pkg.sv"
+
+// parameter A_WIDTH = 8;     // Address bus width
+// parameter D_WIDTH = 128;     // Data bus width
+
+module top;
+    bit clk, rstn;
+
+    always #5 clk = ~clk;
+
+    initial rstn = 1;
+
+    axi_intf#(.A_WIDTH(A_WIDTH), .D_WIDTH(D_WIDTH)) intf(clk, rstn);
+	env_config env_cfg;
+
+    initial begin
+        env_cfg = new();
+        env_cfg.intf = intf;
+        uvm_config_db#(env_config)::set(null, "uvm_test_top", "config", env_cfg);
+        uvm_config_db#(env_config)::set(null, "uvm_test_top.env.master", "config", env_cfg);
+        uvm_config_db#(env_config)::set(null, "uvm_test_top.env.slave", "config", env_cfg);
+        run_test("axi_base_test");
+    end
+    
+endmodule
diff --git a/axi_test.sv b/axi_test.sv
new file mode 100644
index 0000000..68d5687
--- /dev/null
+++ b/axi_test.sv
@@ -0,0 +1,166 @@
+class axi_base_test extends uvm_test;
+    `uvm_component_utils(axi_base_test)
+    
+    // Components
+    axi_env env;
+    axi_write_seq#(.D_WIDTH(D_WIDTH), .A_WIDTH(A_WIDTH)) wr_seq;
+    axi_read_seq#(.D_WIDTH(D_WIDTH), .A_WIDTH(A_WIDTH)) rd_seq;
+
+    // variables
+    env_config env_cfg;
+    test_config test_cfg;
+
+    function new(string name, uvm_component parent);
+        super.new(name, parent);
+        test_cfg = new("test_cfg");
+        test_cfg.no_write_cases = 1;
+        test_cfg.no_read_cases = 1;
+    endfunction //new()
+
+    //  Function: build_phase
+    extern function void build_phase(uvm_phase phase);
+    
+    //  Function: end_of_elaboration_phase
+    extern function void end_of_elaboration_phase(uvm_phase phase);
+    
+    //  Function: run_phase
+    extern task run_phase(uvm_phase phase);
+
+endclass //axi_base_test extends uvm_test
+
+function void axi_base_test::build_phase(uvm_phase phase);
+    test_cfg.burst_type = 2;
+    uvm_config_db#(test_config)::set(null, "uvm_test_top.seq", "config", test_cfg);
+    
+    wr_seq = new("wr_seq");
+    rd_seq = new("rd_seq");
+    env = axi_env::type_id::create("env", this);
+endfunction: build_phase
+
+function void axi_base_test::end_of_elaboration_phase(uvm_phase phase);
+    super.end_of_elaboration_phase(phase);
+    uvm_top.print_topology();
+endfunction: end_of_elaboration_phase
+
+task axi_base_test::run_phase(uvm_phase phase);
+    phase.raise_objection(this);
+    fork
+        wr_seq.start(env.master.w_seqr);
+      #200
+           rd_seq.start(env.master.r_seqr);
+     //  end
+    join
+    phase.drop_objection(this);
+endtask: run_phase
+
+
+// ****************************************************************************************
+//                                  Directed Test Cases
+// ****************************************************************************************
+class axi_write_test extends axi_base_test;
+    `uvm_component_utils(axi_write_test)
+    
+    function new(string name, uvm_component parent);
+        super.new(name, parent);
+    endfunction //new()
+
+    function void build_phase(uvm_phase phase);
+        super.build_phase(phase);  
+    endfunction: build_phase
+
+    function void end_of_elaboration_phase(uvm_phase phase);
+        super.end_of_elaboration_phase(phase);
+    endfunction: end_of_elaboration_phase
+    
+    task run_phase(uvm_phase phase);
+        phase.raise_objection(this);
+        wr_seq.start(env.master.w_seqr);
+        phase.drop_objection(this);
+    endtask: run_phase
+endclass //write_test extends axi_base_test
+
+class axi_read_test extends axi_base_test;
+    `uvm_component_utils(axi_read_test)
+    
+    function new(string name, uvm_component parent);
+        super.new(name, parent);
+    endfunction //new()
+
+    function void build_phase(uvm_phase phase);
+        super.build_phase(phase);  
+    endfunction: build_phase
+
+    function void end_of_elaboration_phase(uvm_phase phase);
+        super.end_of_elaboration_phase(phase);
+    endfunction: end_of_elaboration_phase
+    
+    task run_phase(uvm_phase phase);
+        phase.raise_objection(this);
+        wr_seq.start(env.master.w_seqr);
+      //  rd_seq.start(env.master.r_seqr);
+        phase.drop_objection(this);
+    endtask: run_phase
+endclass //write_test extends axi_base_test
+
+class axi_fixed_test extends axi_base_test;
+    `uvm_component_utils(axi_fixed_test)
+    
+    function new(string name, uvm_component parent);
+        super.new(name, parent);
+    endfunction //new()
+
+    function void build_phase(uvm_phase phase);
+        test_cfg.burst_type = 0;
+        uvm_config_db#(test_config)::set(null, "uvm_test_top.seq", "config", test_cfg);
+        
+        wr_seq = new("wr_seq");
+        rd_seq = new("rd_seq");
+        env = axi_env::type_id::create("env", this);
+    endfunction: build_phase
+
+    task run_phase(uvm_phase phase);
+        super.run_phase(phase);
+    endtask: run_phase
+endclass //axi_fixed_test extends axi_base_test
+
+class axi_incr_test extends axi_base_test;
+    `uvm_component_utils(axi_incr_test)
+    
+    function new(string name, uvm_component parent);
+        super.new(name, parent);
+    endfunction //new()
+
+    function void build_phase(uvm_phase phase);
+        test_cfg.burst_type = 1;
+        uvm_config_db#(test_config)::set(null, "uvm_test_top.seq", "config", test_cfg);
+        
+        wr_seq = new("wr_seq");
+        rd_seq = new("rd_seq");
+        env = axi_env::type_id::create("env", this);
+    endfunction: build_phase
+
+    task run_phase(uvm_phase phase);
+        super.run_phase(phase);
+    endtask: run_phase
+endclass //axi_fixed_test extends axi_base_test
+
+class axi_wrap_test extends axi_base_test;
+    `uvm_component_utils(axi_wrap_test)
+    
+    function new(string name, uvm_component parent);
+        super.new(name, parent);
+    endfunction //new()
+
+    function void build_phase(uvm_phase phase);
+        test_cfg.burst_type = 2;
+        uvm_config_db#(test_config)::set(null, "uvm_test_top.seq", "config", test_cfg);
+        
+        wr_seq = new("wr_seq");
+        rd_seq = new("rd_seq");
+        env = axi_env::type_id::create("env", this);
+    endfunction: build_phase
+
+    task run_phase(uvm_phase phase);
+        super.run_phase(phase);
+    endtask: run_phase
+endclass //axi_fixed_test extends axi_base_test
diff --git a/axi_transaction.sv b/axi_transaction.sv
index e3166ad..045a081 100644
--- a/axi_transaction.sv
+++ b/axi_transaction.sv
@@ -1,125 +1,185 @@
-`include "uvm_macros.svh"
-import uvm_pkg::*;
-
-class axi_seq_item extends uvm_seq_item;
-//'uvm_object_utils(axi_seq_item);
-
-function new(string name="axi_seq_item")
-super.new(name);
-endfunction
-//write adress channel signals
-
-rand bit wr_rd;
-
-rand bit [3:0] awid;
-rand logic[31:0] awaddr;
-rand logic[2:0] awsize;
-rand logic[3:0] awlen;
-rand logic[1:0] awburst;
-rand logic[1:0] awlock;
-
-logic awvalid;
-logic awready;
-
-
-  //write data channel 
-
-rand bit [3:0] wid;
-rand logic[31:0] wdata[][];
-logic[3:0] wstrb;
-logic wlast;
-logic wvalid;
-logic wready;
-
-// write response channel
-rand bit []3:0]bid;
-logic[1:0] bresp;
-
-logic bvalid;
-logic bready;
-  
-// read adress channel
-
-rand bit [3:0] arid;
-
-rand logic[31:0] araddr;
-rand logic[2:0] arsize;
-rand logic[3:0] arlen;
-rand logic[1:0] arburst;
-rand logic[1:0] arlock;
-logic arvalid;
-logic arready;
-    
-// read data channel
-
-
-rand bit [3:0] rid;
- logic[31:0] rdata;
- logic[3:0]rresp;
-logic rlast;
-logic rvalid;
-logic rready;
-
-
-`uvm_object_utils_begin(axi_seq_item)
-
-`uvm_field_int(awid,UVM_ALL_ON)
-`uvm_field_int(awaddr,UVM_ALL_ON)
-`uvm_field_int(awsize,UVM_ALL_ON)
-`uvm_field_int(awlen,UVM_ALL_ON)
-`uvm_field_int(awburst,UVM_ALL_ON)
-`uvm_field_int(awlock,UVM_ALL_ON)
-`uvm_field_int(awvalid,UVM_ALL_ON)
-`uvm_field_int(awready,UVM_ALL_ON)
-
-`uvm_field_int(wid,UVM_ALL_ON)
-`uvm_field_int(wdata,UVM_ALL_ON)
-`uvm_field_int(wlast,UVM_ALL_ON)
-`uvm_field_int(wstrb,UVM_ALL_ON)
-`uvm_field_int(wvalid,UVM_ALL_ON)
-`uvm_field_int(wready,UVM_ALL_ON)
-
-`uvm_field_int(bid,UVM_ALL_ON)
-`uvm_field_int(bresp,UVM_ALL_ON)
-`uvm_field_int(bvalid,UVM_ALL_ON)
-`uvm_field_int(bready,UVM_ALL_ON)
-
-`uvm_field_int(arid,UVM_ALL_ON)
-`uvm_field_int(araddr,UVM_ALL_ON)
-`uvm_field_int(arsize,UVM_ALL_ON)
-`uvm_field_int(arlen,UVM_ALL_ON)
-`uvm_field_int(arsize,UVM_ALL_ON)
-`uvm_field_int(arburst,UVM_ALL_ON)
-`uvm_field_int(arlock,UVM_ALL_ON)
-`uvm_field_int(arvalid,UVM_ALL_ON)
-`uvm_field_int(arready,UVM_ALL_ON)
-
-`uvm_field_int(rid,UVM_ALL_ON)
-`uvm_field_int(rdata,UVM_ALL_ON)
-`uvm_field_int(rlast,UVM_ALL_ON)
-`uvm_field_int(rresp,UVM_ALL_ON)
-`uvm_field_int(rvalid,UVM_ALL_ON)
-`uvm_field_int(rready,UVM_ALL_ON)
-
-`uvm_object_utils_end
-
-//constraints for axi
-
-constraint aligned_addr{awadd%2**awsize==0;}
-
-constraint wrap_addr{solve awburst before awlen
-                     if(awburst==2'b 10)
-                     awlen inside{1,3,7,15};}
-
-constraint wid_sig{awid==wid;}
-
-constraint rid_sig{arid==rid;}
-
-constraint axi_4kb{awaddr%4096+(2**awsize*(awlen+1))<=4096;}
-
-
-
-//:constrain
-endclass:axi_seq_item
-
-
+import uvm_pkg::*;
+typedef enum bit[1:0] { FIXED, INCR, WRAP } B_TYPE;
+//  Class: axi_transaction
+//
+class axi_transaction#(d_width = 16, a_width = 16) extends uvm_sequence_item;
+    typedef axi_transaction#(d_width, a_width) this_type_t;
+    `uvm_object_param_utils(axi_transaction#(d_width, a_width));
+    
+
+    //  Group: Variables
+    bit [8:0] id;
+    rand bit [a_width-1:0] addr;
+    rand bit write;
+    rand bit [7:0] data [][];
+    rand bit [2:0] b_size;
+    rand bit [3:0] b_len;
+    rand B_TYPE b_type;
+    bit b_last;
+    bit [1:0] b_resp;
+    bit [1:0] r_resp [];
+
+    
+
+    //  Group: Constraints
+    constraint b_size_val { 8*(2**b_size) <= d_width; }
+
+    constraint data_size {
+        /*  solve order constraints  */
+        solve b_len before data;
+        solve b_size before data;
+
+        /*  rand variable constraints  */
+        data.size() == b_len+1;
+        foreach (data[i] )
+            data[i].size() == 2**b_size;
+    }
+    
+
+    constraint b_len_val {
+        /*  solve order constraints  */
+        solve b_type before b_len;
+
+        /*  rand variable constraints  */
+        if(b_type == FIXED)
+            b_len inside { 0, 1 };
+        else if(b_type == WRAP)
+            b_len inside { 1, 3, 7, 15 };
+    }
+    
+    constraint addr_val {
+        /*  solve order constraints  */
+        solve b_type before addr;
+        solve b_size before addr;
+
+        /*  rand variable constraints  */
+        if(b_type == WRAP)
+            addr == int'(addr/2**b_size) * 2**b_size;
+    }
+
+    constraint addr_val_align {
+        /*  solve order constraints  */
+        solve b_size before addr;
+
+        /*  rand variable constraints  */
+        addr == int'(addr/2**b_size) * 2**b_size;
+    }
+
+    constraint addr_val_unalign {
+        /*  solve order constraints  */
+        solve b_size before addr;
+
+        /*  rand variable constraints  */
+        addr != int'(addr/2**b_size) * 2**b_size;
+    }
+
+    //  Constructor: new
+    function new(string name = "axi_transaction");
+        super.new(name);
+    endfunction: new
+
+    //  Function: do_copy
+    extern function void do_copy(uvm_object rhs);
+    //  Function: do_compare
+    extern function bit do_compare(uvm_object rhs, uvm_comparer comparer);
+    //  Function: convert2string
+    extern function string convert2string();
+    //  Function: do_print
+    extern function void do_print(uvm_printer printer);
+    //  Function: do_record
+    // extern function void do_record(uvm_recorder recorder);
+    //  Function: do_pack
+    // extern function void do_pack();
+    //  Function: do_unpack
+    // extern function void do_unpack();
+    
+endclass: axi_transaction
+
+/*----------------------------------------------------------------------------*/
+/*  Functions                                                                 */
+/*----------------------------------------------------------------------------*/
+function void axi_transaction::do_print(uvm_printer printer);
+    /*  chain the print with parent classes  */
+    super.do_print(printer);
+
+    /*  list of local properties to be printed:  */
+    printer.print_field("ID", id, $bits(id), UVM_UNSIGNED);
+    printer.print_field("Addr", addr, $bits(addr), UVM_HEX);
+    printer.print_generic("Data", "dynamic array", 8*2**b_size*(b_len+1), $sformatf("%u", data));
+    printer.print_field("Burst Size", b_size, $bits(b_size), UVM_UNSIGNED);
+    printer.print_field("Burst Length", b_len+1, $bits(b_len), UVM_UNSIGNED);
+    printer.print_generic("Burst Type", "B_TYPE", $bits(b_len), b_type.name());
+endfunction: do_print
+
+function string axi_transaction::convert2string();
+    string s;
+
+    /*  chain the convert2string with parent classes  */
+    s = super.convert2string();
+
+    /*  list of local properties to be printed:  */
+    //  guide             0---4---8--12--16--20--24--28--32--36--40--44--48--
+    s = {s, $sformatf("ID             :   %0d\n", id)};
+    s = {s, $sformatf("Addr           : 0x%0h\n", addr)};
+    s = {s, $sformatf("Data           : 0x%0u\n", data)};
+    s = {s, $sformatf("Busrt Type     :   %s\n", b_type.name())};
+    s = {s, $sformatf("Burst Size     :   %0d\n", b_size)};
+    s = {s, $sformatf("Busrt Length   :   %0d\n", b_len+1)};
+    s = {s, $sformatf("Busrt resp     : 0x%0h\n", b_resp)};
+    s = {s, $sformatf("Read resp      :   %0u\n", r_resp)};
+    return s;
+endfunction: convert2string
+
+function void axi_transaction::do_copy(uvm_object rhs);
+    this_type_t rhs_;
+
+    if (!$cast(rhs_, rhs)) begin
+        `uvm_error({this.get_name(), ".do_copy()"}, "Cast failed!");
+        return;
+    end
+    // `uvm_info({this.get_name(), ".do_copy()"}, "Cast succeded.", UVM_HIGH);
+
+    /*  chain the copy with parent classes  */
+    super.do_copy(rhs);
+
+    /*  list of local properties to be copied  */
+    this.id     = rhs_.id;
+    this.addr   = rhs_.addr;
+    this.data   = rhs_.data;
+    this.b_type = rhs_.b_type;
+    this.b_size = rhs_.b_size;
+    this.b_len  = rhs_.b_len;
+    this.b_resp = rhs_.b_resp;
+    this.r_resp = rhs_.r_resp;
+endfunction: do_copy
+
+function bit axi_transaction::do_compare(uvm_object rhs, uvm_comparer comparer);
+    this_type_t rhs_;
+
+    if (!$cast(rhs_, rhs)) begin
+        `uvm_error({this.get_name(), ".do_compare()"}, "Cast failed!");
+        return 0;
+    end
+    // `uvm_info({this.get_name(), ".do_compare()"}, "Cast succeded.", UVM_HIGH);
+
+    /*  chain the compare with parent classes  */
+    do_compare = super.do_compare(rhs, comparer);
+
+    /*  list of local properties to be compared:  */
+    do_compare &= (
+        this.id == rhs_.id &&
+        this.addr == rhs_.addr &&
+        this.b_type == rhs_.b_type &&
+        this.b_size == rhs_.b_size &&
+        this.b_len == rhs_.b_len &&
+        this.b_resp == rhs_.b_resp 
+    );
+
+    foreach(data[i,j]) begin
+        do_compare &= this.data[i][j] == rhs_.data[i][j];
+    end
+
+    foreach ( r_resp[i] ) begin
+        do_compare &= this.r_resp[i] == rhs_.r_resp[i];
+    end
+endfunction: do_compare
\ No newline at end of file
diff --git a/axi_write_seq.sv b/axi_write_seq.sv
new file mode 100644
index 0000000..2f407d3
--- /dev/null
+++ b/axi_write_seq.sv
@@ -0,0 +1,61 @@
+//  Class: axi_write_seq
+//
+class axi_write_seq#(D_WIDTH = 16, int A_WIDTH = 16) extends uvm_sequence;
+    `uvm_object_param_utils(axi_write_seq#(D_WIDTH, A_WIDTH));
+    
+    //  Group: Variables
+    const int no_of_trans;
+    bit[7:0] id;
+    axi_transaction#(D_WIDTH, A_WIDTH) trans;
+    test_config test_cfg;
+
+    //  Constructor: new
+    function new(string name = "axi_write_seq");
+        super.new(name);
+        test_cfg = new("test_cfg");
+        if(!uvm_config_db#(test_config)::get(null, "uvm_test_top.seq", "config", test_cfg)) 
+            `uvm_fatal(get_name(), "config cannot be found in ConfigDB!")
+        
+        no_of_trans = test_cfg.no_write_cases;
+    endfunction: new
+
+    //  Task: body
+    //  This is the user-defined task where the main sequence code resides.
+    extern virtual task body();
+    
+endclass: axi_write_seq
+
+task axi_write_seq::body();
+    repeat(no_of_trans) begin
+        id++;
+        trans = axi_transaction#(D_WIDTH, A_WIDTH)::type_id::create("trans");
+        if(test_cfg.isAligned) begin
+            trans.addr_val_align.constraint_mode(1);
+            trans.addr_val_unalign.constraint_mode(0);
+            trans.addr_val.constraint_mode(0);
+        end
+        else if (!test_cfg.isAligned) begin
+            trans.addr_val_align.constraint_mode(0);
+            trans.addr_val_unalign.constraint_mode(1);
+            trans.addr_val.constraint_mode(0);
+        end
+        else begin
+            trans.addr_val_align.constraint_mode(0);
+            trans.addr_val_unalign.constraint_mode(0);
+            trans.addr_val.constraint_mode(1);
+        end
+        start_item(trans);
+        if(test_cfg.burst_type == 0)
+            assert(trans.randomize() with { b_type == FIXED; });
+        else if(test_cfg.burst_type == 1)
+            assert(trans.randomize() with { b_type == INCR; });
+        else if(test_cfg.burst_type == 2)
+            assert(trans.randomize() with { b_type == WRAP; addr==16'h80c6;write==1;});
+        else
+            assert(trans.randomize());
+        trans.id = {1'b0, id};
+        finish_item(trans);
+        trans.print();
+        #10;
+    end
+endtask: body