Subversion Repositories test_project

`timescale 1ns/10ps
module tap_top(
                tms_pad_i, 
                tck_pad_i, 
                trst_pad_i, 
                tdi_pad_i, 
                tdo_pad_o, 
                tdo_padoe_o,
                shift_dr_o,
                pause_dr_o, 
                update_dr_o,
                capture_dr_o,
                extest_select_o, 
                sample_preload_select_o,
                mbist_select_o,
                debug_select_o,
                tdo_o, 
                debug_tdi_i,    
                bs_chain_tdi_i, 
                mbist_tdi_i     
              );
input   tms_pad_i;      
input   tck_pad_i;      
input   trst_pad_i;     
input   tdi_pad_i;      
output  tdo_pad_o;      
output  tdo_padoe_o;    
output  shift_dr_o;
output  pause_dr_o;
output  update_dr_o;
output  capture_dr_o;
output  extest_select_o;
output  sample_preload_select_o;
output  mbist_select_o;
output  debug_select_o;
output  tdo_o;
input   debug_tdi_i;    
input   bs_chain_tdi_i; 
input   mbist_tdi_i;    
reg     test_logic_reset;
reg     run_test_idle;
reg     select_dr_scan;
reg     capture_dr;
reg     shift_dr;
reg     exit1_dr;
reg     pause_dr;
reg     exit2_dr;
reg     update_dr;
reg     select_ir_scan;
reg     capture_ir;
reg     shift_ir, shift_ir_neg;
reg     exit1_ir;
reg     pause_ir;
reg     exit2_ir;
reg     update_ir;
reg     extest_select;
reg     sample_preload_select;
reg     idcode_select;
reg     mbist_select;
reg     debug_select;
reg     bypass_select;
reg     tdo_pad_o;
reg     tdo_padoe_o;
reg     tms_q1, tms_q2, tms_q3, tms_q4;
wire    tms_reset;
assign tdo_o = tdi_pad_i;
assign shift_dr_o = shift_dr;
assign pause_dr_o = pause_dr;
assign update_dr_o = update_dr;
assign capture_dr_o = capture_dr;
assign extest_select_o = extest_select;
assign sample_preload_select_o = sample_preload_select;
assign mbist_select_o = mbist_select;
assign debug_select_o = debug_select;
always @ (posedge tck_pad_i)
begin
  tms_q1 <= #1 tms_pad_i;
  tms_q2 <= #1 tms_q1;
  tms_q3 <= #1 tms_q2;
  tms_q4 <= #1 tms_q3;
end
assign tms_reset = tms_q1 & tms_q2 & tms_q3 & tms_q4 & tms_pad_i;    
always @ (posedge tck_pad_i or posedge trst_pad_i)
begin
  if(trst_pad_i)
    test_logic_reset<=#1 1'b1;
  else if (tms_reset)
    test_logic_reset<=#1 1'b1;
  else
    begin
      if(tms_pad_i & (test_logic_reset | select_ir_scan))
        test_logic_reset<=#1 1'b1;
      else
        test_logic_reset<=#1 1'b0;
    end
end
always @ (posedge tck_pad_i or posedge trst_pad_i)
begin
  if(trst_pad_i)
    run_test_idle<=#1 1'b0;
  else if (tms_reset)
    run_test_idle<=#1 1'b0;
  else
  if(~tms_pad_i & (test_logic_reset | run_test_idle | update_dr | update_ir))
    run_test_idle<=#1 1'b1;
  else
    run_test_idle<=#1 1'b0;
end
always @ (posedge tck_pad_i or posedge trst_pad_i)
begin
  if(trst_pad_i)
    select_dr_scan<=#1 1'b0;
  else if (tms_reset)
    select_dr_scan<=#1 1'b0;
  else
  if(tms_pad_i & (run_test_idle | update_dr | update_ir))
    select_dr_scan<=#1 1'b1;
  else
    select_dr_scan<=#1 1'b0;
end
always @ (posedge tck_pad_i or posedge trst_pad_i)
begin
  if(trst_pad_i)
    capture_dr<=#1 1'b0;
  else if (tms_reset)
    capture_dr<=#1 1'b0;
  else
  if(~tms_pad_i & select_dr_scan)
    capture_dr<=#1 1'b1;
  else
    capture_dr<=#1 1'b0;
end
always @ (posedge tck_pad_i or posedge trst_pad_i)
begin
  if(trst_pad_i)
    shift_dr<=#1 1'b0;
  else if (tms_reset)
    shift_dr<=#1 1'b0;
  else
  if(~tms_pad_i & (capture_dr | shift_dr | exit2_dr))
    shift_dr<=#1 1'b1;
  else
    shift_dr<=#1 1'b0;
end
always @ (posedge tck_pad_i or posedge trst_pad_i)
begin
  if(trst_pad_i)
    exit1_dr<=#1 1'b0;
  else if (tms_reset)
    exit1_dr<=#1 1'b0;
  else
  if(tms_pad_i & (capture_dr | shift_dr))
    exit1_dr<=#1 1'b1;
  else
    exit1_dr<=#1 1'b0;
end
always @ (posedge tck_pad_i or posedge trst_pad_i)
begin
  if(trst_pad_i)
    pause_dr<=#1 1'b0;
  else if (tms_reset)
    pause_dr<=#1 1'b0;
  else
  if(~tms_pad_i & (exit1_dr | pause_dr))
    pause_dr<=#1 1'b1;
  else
    pause_dr<=#1 1'b0;
end
always @ (posedge tck_pad_i or posedge trst_pad_i)
begin
  if(trst_pad_i)
    exit2_dr<=#1 1'b0;
  else if (tms_reset)
    exit2_dr<=#1 1'b0;
  else
  if(tms_pad_i & pause_dr)
    exit2_dr<=#1 1'b1;
  else
    exit2_dr<=#1 1'b0;
end
always @ (posedge tck_pad_i or posedge trst_pad_i)
begin
  if(trst_pad_i)
    update_dr<=#1 1'b0;
  else if (tms_reset)
    update_dr<=#1 1'b0;
  else
  if(tms_pad_i & (exit1_dr | exit2_dr))
    update_dr<=#1 1'b1;
  else
    update_dr<=#1 1'b0;
end
always @ (posedge tck_pad_i or posedge trst_pad_i)
begin
  if(trst_pad_i)
    select_ir_scan<=#1 1'b0;
  else if (tms_reset)
    select_ir_scan<=#1 1'b0;
  else
  if(tms_pad_i & select_dr_scan)
    select_ir_scan<=#1 1'b1;
  else
    select_ir_scan<=#1 1'b0;
end
always @ (posedge tck_pad_i or posedge trst_pad_i)
begin
  if(trst_pad_i)
    capture_ir<=#1 1'b0;
  else if (tms_reset)
    capture_ir<=#1 1'b0;
  else
  if(~tms_pad_i & select_ir_scan)
    capture_ir<=#1 1'b1;
  else
    capture_ir<=#1 1'b0;
end
always @ (posedge tck_pad_i or posedge trst_pad_i)
begin
  if(trst_pad_i)
    shift_ir<=#1 1'b0;
  else if (tms_reset)
    shift_ir<=#1 1'b0;
  else
  if(~tms_pad_i & (capture_ir | shift_ir | exit2_ir))
    shift_ir<=#1 1'b1;
  else
    shift_ir<=#1 1'b0;
end
always @ (posedge tck_pad_i or posedge trst_pad_i)
begin
  if(trst_pad_i)
    exit1_ir<=#1 1'b0;
  else if (tms_reset)
    exit1_ir<=#1 1'b0;
  else
  if(tms_pad_i & (capture_ir | shift_ir))
    exit1_ir<=#1 1'b1;
  else
    exit1_ir<=#1 1'b0;
end
always @ (posedge tck_pad_i or posedge trst_pad_i)
begin
  if(trst_pad_i)
    pause_ir<=#1 1'b0;
  else if (tms_reset)
    pause_ir<=#1 1'b0;
  else
  if(~tms_pad_i & (exit1_ir | pause_ir))
    pause_ir<=#1 1'b1;
  else
    pause_ir<=#1 1'b0;
end
always @ (posedge tck_pad_i or posedge trst_pad_i)
begin
  if(trst_pad_i)
    exit2_ir<=#1 1'b0;
  else if (tms_reset)
    exit2_ir<=#1 1'b0;
  else
  if(tms_pad_i & pause_ir)
    exit2_ir<=#1 1'b1;
  else
    exit2_ir<=#1 1'b0;
end
always @ (posedge tck_pad_i or posedge trst_pad_i)
begin
  if(trst_pad_i)
    update_ir<=#1 1'b0;
  else if (tms_reset)
    update_ir<=#1 1'b0;
  else
  if(tms_pad_i & (exit1_ir | exit2_ir))
    update_ir<=#1 1'b1;
  else
    update_ir<=#1 1'b0;
end
reg [4-1:0]  jtag_ir;          
reg [4-1:0]  latched_jtag_ir, latched_jtag_ir_neg;
reg                   instruction_tdo;
always @ (posedge tck_pad_i or posedge trst_pad_i)
begin
  if(trst_pad_i)
    jtag_ir[4-1:0] <= #1 4'b0;
  else if(capture_ir)
    jtag_ir <= #1 4'b0101;          
  else if(shift_ir)
    jtag_ir[4-1:0] <= #1 {tdi_pad_i, jtag_ir[4-1:1]};
end
always @ (negedge tck_pad_i)
begin
  instruction_tdo <= #1 jtag_ir[0];
end
reg [31:0] idcode_reg;
reg        idcode_tdo;
always @ (posedge tck_pad_i)
begin
  if(idcode_select & shift_dr)
    idcode_reg <= #1 {tdi_pad_i, idcode_reg[31:1]};
  else
    idcode_reg <= #1 32'h14951185;
end
always @ (negedge tck_pad_i)
begin
    idcode_tdo <= #1 idcode_reg;
end
reg  bypassed_tdo;
reg  bypass_reg;
always @ (posedge tck_pad_i or posedge trst_pad_i)
begin
  if (trst_pad_i)
    bypass_reg<=#1 1'b0;
  else if(shift_dr)
    bypass_reg<=#1 tdi_pad_i;
end
always @ (negedge tck_pad_i)
begin
  bypassed_tdo <=#1 bypass_reg;
end
always @ (posedge tck_pad_i or posedge trst_pad_i)
begin
  if(trst_pad_i)
    latched_jtag_ir <=#1 4'b0010;   
  else if (tms_reset)
    latched_jtag_ir <=#1 4'b0010;   
  else if(update_ir)
    latched_jtag_ir <=#1 jtag_ir;
end
always @ (latched_jtag_ir)
begin
  extest_select           = 1'b0;
  sample_preload_select   = 1'b0;
  idcode_select           = 1'b0;
  mbist_select            = 1'b0;
  debug_select            = 1'b0;
  bypass_select           = 1'b0;
  case(latched_jtag_ir)     
    4'b0000:            extest_select           = 1'b1;    
    4'b0001:    sample_preload_select   = 1'b1;    
    4'b0010:            idcode_select           = 1'b1;    
    4'b1001:             mbist_select            = 1'b1;    
    4'b1000:             debug_select            = 1'b1;    
    4'b1111:            bypass_select           = 1'b1;    
    default:            bypass_select           = 1'b1;    
  endcase
end
always @ (shift_ir_neg or exit1_ir or instruction_tdo or latched_jtag_ir_neg or idcode_tdo or
          debug_tdi_i or bs_chain_tdi_i or mbist_tdi_i or 
          bypassed_tdo)
begin
  if(shift_ir_neg)
    tdo_pad_o = instruction_tdo;
  else
    begin
      case(latched_jtag_ir_neg)    
        4'b0010:            tdo_pad_o = idcode_tdo;       
        4'b1000:             tdo_pad_o = debug_tdi_i;      
        4'b0001:    tdo_pad_o = bs_chain_tdi_i;   
        4'b0000:            tdo_pad_o = bs_chain_tdi_i;   
        4'b1001:             tdo_pad_o = mbist_tdi_i;      
        default:            tdo_pad_o = bypassed_tdo;     
      endcase
    end
end
always @ (negedge tck_pad_i)
begin
  tdo_padoe_o <= #1 shift_ir | shift_dr | (pause_dr & debug_select);
end
always @ (negedge tck_pad_i)
begin
  shift_ir_neg <= #1 shift_ir;
  latched_jtag_ir_neg <= #1 latched_jtag_ir;
end
endmodule