/*`timescale 1ns / 1ns
//////////////////////////////////////////////////////////////////////////////////
// Company: 
// Engineer: 
// 
// Create Date: 02/24/2021 08:03:07 PM
// Design Name: 
// Module Name: sc_decoder_fsm
// Project Name: 
// Target Devices: 
// Tool Versions: 
// Description: 
// 
// Dependencies: 
// 
// Revision:
// Revision 0.01 - File Created
// Additional Comments:
// 
//////////////////////////////////////////////////////////////////////////////////
`define BITS 8
module sc_decoder_fsm #(parameter BITS=8, N=11'd16)(
input clk, rst,
input in_valid,
input signed [N-1:0][BITS-1:0]y,
input [N-1:0]f, 
output logic [N-1:0]u_cap,
output logic [N-1:0]v_final,
output logic out_valid
);


// Function to calculate f(r1,r2) = sgn(r1) * sgn(r2) * min(|r1|,|r2|)
function void fminsum_calc;
        input  signed [`BITS-1:0] a;
        input  signed [`BITS-1:0] b;
        output signed [`BITS-1:0] c;
        
        logic [`BITS-2:0] abs_a;
        logic [`BITS-2:0] abs_b;
        logic [`BITS-2:0] abs_c;
        
        // Mod value of a and b  
        abs_a = (a[`BITS-1]) ? ~a[`BITS-2:0] + 1'b1 : a[`BITS-2:0];
        abs_b = (b[`BITS-1]) ? ~b[`BITS-2:0] + 1'b1 : b[`BITS-2:0];
        
        // Multiplication of sign i.e. XOR
        c[`BITS-1] = a[`BITS-1] ^ b[`BITS-1];
        
        // Minimum value between a and b
        abs_c = (abs_b < abs_a) ? abs_b : abs_a;
        
        // Final Minsum of a and b
        c[`BITS-2:0] = (c[`BITS-1]) ? ~abs_c + 1'b1 : abs_c;
        
endfunction
    

// Function to Calculate g(r1,r2,u) = r2 + ((1-2u) * r1)
function  void g_calc;
        input signed [`BITS-1:0] a;
        input signed [`BITS-1:0] b;
        input u;
        output signed [`BITS:0] c;
        
       // when u == 0 => c = b - a 
       // When u == 1 => c = b + a  
        c = u  ? (b + (~a+1)) : (b + a) ;
endfunction


//parameters and signals declarations
localparam d=$clog2(N);  //N=4, d=2(0 & 1)
logic [N-1:0]u;
logic [d:0]temp_index_f,temp_index_g;
reg signed [BITS-1:0] LRU[2];
reg [N-1:0]v;
logic [N-1:0][BITS-1:0]L_in, L_out;
logic [N-1:0]v_in, v_out;
logic ena_v,enb_v,wea_v;
logic ena_L,enb_L,wea_L;
logic [1:0]counter,counter_reg;
logic [11:0]jL1,jL2,jR1,jR2,jR3,jU1,jU2;
logic [4:0] c_state, n_state;


wire [N-1:0]u_cap_1;  
wire [N-1:0]v_final_1;
//wire out_valid_1;

      
//Auxiliary registers declarations
logic [d:0] depth,depth_reg;
logic [d:0] node,node_reg;
logic [11:0]tmp_L,tmp_L_reg, tmp_R,tmp_R_reg,tmp_U, tmp_U_reg;

//FSM States
localparam idle=5'd0, root=5'd1, wait_L_logic=5'd2, wait_L=5'd3, state_L=5'd4, wait_R_logic=5'd5, wait_R=5'd6, state_R=5'd7;
localparam wait_U_logic=5'd8, wait_U=5'd9, state_U=5'd10,wait_LRU_logic=5'd11, wait_LRU=5'd12, state_LRU=5'd13;
localparam wait_lnode_logic=5'd14, wait_lnode=5'd15, state_lnode=5'd16,wait_lstate_logic=5'd17, wait_lstate=5'd18, state_last=5'd19;

//BlockRAM Instantiations
 bram_v #(.ADDR_WIDTH(d-1),.DATA_WIDTH(N),.DEPTH(2**(d-1))) bram_v_i (
.clk(clk),.ena(ena_v),.enb(enb_v),
.addra(depth_reg-1'b1),
.addrb(depth_reg),
.wea(wea_v),
.dia(v_in),
.dob(v_out)
);

bram_L #(.ADDR_WIDTH(d-1),.DATA_WIDTH(N*BITS),.DEPTH(2**(d-1)),.N(N)) bram_L_i (
.clk(clk),.ena(ena_L),.enb(enb_L),
.addra(depth_reg),
.addrb(depth_reg-1'b1),
.wea(wea_L),
.dia(L_in),
.dob(L_out)
);

//output assignment
for(genvar i=0; i<N; i++)
 begin
 assign u_cap_1[i] = u[i];
 end
 assign v_final_1 = v;
 
//  assign out_valid_1 = (n_state == state_lnode) ? 1'b1 : 1'b0;
 assign out_valid=(n_state==state_last)?1'b1:1'b0;


// Sequential Logic - FSM State and Data Registers
always_ff@(posedge clk) 
begin
    if(rst==1) 
    begin
        u_cap     <= 'b0;
        v_final   <= 'b0;
 
        c_state <= idle;
        depth_reg<=0;
        node_reg<=0;
        counter_reg<=0;
        tmp_L_reg<=0;
        tmp_R_reg<=0;
        tmp_U_reg<=0;
     end
    else 
    begin
//        out_valid <= out_valid_1;          
//        v_final   <= v_final_1;
        if(out_valid)
           begin
             u_cap     <= u;
          end
        else
          begin
             u_cap     <= u_cap;
          end
        c_state <= n_state;
        depth_reg<=depth;
        node_reg<=node;
        counter_reg<=counter;
        tmp_L_reg<=tmp_L;
        tmp_R_reg<=tmp_R;
        tmp_U_reg<=tmp_U;
    end
end

//Combinational Logic - FSM Next State Logic
always_comb 
begin  
//                  depth=0; node=0;  
 //                   ena_L=0;wea_L=0;enb_L=0;
                    tmp_L=0; tmp_R=0; tmp_U=0;
                   counter=0; ena_v=0;wea_v=0; enb_v=0; n_state = 0;
  if(in_valid==1)
    case(c_state)
    idle:       begin 
                   depth=0; node=0; counter=0; tmp_L=0; tmp_R=0; tmp_U=0;
                   ena_L=0;wea_L=0;enb_L=0;
                   ena_v=0;wea_v=0; enb_v=0;
                    if(out_valid==1)
                        n_state=idle;
                    else
                        n_state=root;    
                end
          
    root:       begin
                  depth=depth_reg;node=node_reg;
                  ena_L=1;wea_L=1;enb_L=0;
                  ena_v=0;wea_v=0; enb_v=0;     
                  for(int k=0; k<N; k++)
                  L_in[k]=y[k];
                  n_state=wait_L_logic;
                end
   wait_L_logic: 
                begin
                 depth=depth_reg+1; node=((2*node_reg)+1); tmp_L=0;
                 ena_L=0;wea_L=0;enb_L=1;
                 ena_v=0;wea_v=0; enb_v=0; 
                 n_state=wait_L;
                end
    wait_L:    begin
                  n_state=state_L; 
               end
    state_L:    begin     
                    ena_L=1;wea_L=1;enb_L=0;
                    ena_v=0;wea_v=0; enb_v=0;
                    tmp_L=tmp_L_reg+1;
                    temp_index_f=((N/(2**(depth+1)))*((2*(node)+1)-((2**(depth+1))-1))); 
//                    temp_index_f=((N>>(2**(depth+1)))*((2*(node)+1)-((2**(depth+1))-1))); 
                    jL1=(tmp_L_reg)+temp_index_f;
                    jL2=(tmp_L_reg)+temp_index_f+(N/(2**depth));
//                    jL2=(tmp_L_reg)+temp_index_f+(N>>(2**depth));
                    fminsum_calc(L_out[jL1],L_out[jL2],L_in[jL1]); 
                                                               
                    if(tmp_L< (N/(2**depth)))    
//                    if(tmp_L< (N>>(2**depth)))    
                        n_state=state_L;                 
                    else if(depth<d)
                        n_state=wait_L_logic;
                    else
                        n_state=wait_LRU_logic;
                end

     wait_R_logic: begin
                    depth=depth_reg-1; node=node_reg+1; tmp_R=0;
                    n_state=wait_R;
                   end                       
     wait_R:      begin
                    ena_L=0;wea_L=0;enb_L=1;
                    ena_v=0;wea_v=0; enb_v=1; 
                    n_state=state_R; 
                 end                       
    
    state_R:    begin 
                   ena_L=1;wea_L=1;enb_L=0;
                   ena_v=0;wea_v=0; enb_v=0;
                   tmp_R=tmp_R_reg+1;
                   temp_index_f=((N/(2**(depth+1)))*((2*(node)+1)-((2**(depth+1))-1)));
                   temp_index_g=((N/(2**(depth+1)))*((2*(node-1)+1)-((2**(depth+1))-1)));
                   jR1=(tmp_R_reg)+temp_index_g;
                   jR2=(tmp_R_reg)+temp_index_g+(N/(2**depth));
                   jR3=(tmp_R_reg)+temp_index_f;
                   g_calc(L_out[jR1],L_out[jR2],v_out[jR1],L_in[jR3]);
                      
                   if(tmp_R< (N/(2**depth)))    
                       n_state=state_R;
                   else if(node==((2**d)-2)) 
                       n_state=wait_lnode_logic;
                   else if(depth==d)
                       n_state=wait_LRU_logic;
                   else 
                       n_state = wait_L_logic;                                               
               end                   
                            
     wait_U_logic: begin
                     depth=depth_reg-1; node=(node_reg-2)/2; tmp_U=0;
                     n_state=wait_U;
                   end                       
     wait_U:     begin
                     ena_L=0;wea_L=0;enb_L=0;
                     ena_v=0;wea_v=0; enb_v=1; 
                     n_state=state_U; 
                 end                        
    state_U:    begin
                     ena_L=0;wea_L=0;enb_L=0;
                     ena_v=1;wea_v=1; enb_v=0;
                     tmp_U=tmp_U_reg+1;
                     temp_index_f=((N/(2**(depth)))*((2*node+1)-((2**(depth))-1))); 
                     jU1=(tmp_U_reg)+temp_index_f;
                     jU2=(tmp_U_reg)+temp_index_f+(N/(2**(depth)));
                     v_in[jU1] = v_out[jU1] ^ v_out[jU2]; 
                     v_in[jU2] = v_out[jU2]; 
                                    
                     if(tmp_U<(N/(2**(depth)))) 
                         n_state=state_U;
//                     else if(depth>0 && node%2==0)  
                     else if(depth>0 && node[0]==0)  
                         n_state = wait_U_logic;                          
                     else if(depth>0 && node!=0)
                         n_state=wait_R_logic;
                     else              
                         n_state=wait_lstate_logic;         
                  end 
    wait_LRU_logic: begin
                     depth=depth_reg; node=(node_reg-1)/2;
//                     depth=depth_reg; node=(node_reg-1)>>1;
                      n_state=wait_LRU;
                    end                         
    wait_LRU:   begin
                    ena_L=0;wea_L=0;enb_L=1;
                    ena_v=0;wea_v=0; enb_v=0; 
                    n_state=state_LRU; 
                end                                                            
 
    state_LRU:  begin
                    ena_L=0;wea_L=0;enb_L=0;
                    ena_v=1;wea_v=1; enb_v=0;
                    temp_index_f=((N/(2**(depth)))*((2*node+1)-((2**(depth))-1)));
//                    temp_index_f=((N>>(2**(depth)))*((2*node+1)-((2**(depth))-1)));
                    fminsum_calc(L_out[temp_index_f],L_out[temp_index_f+1],LRU[0]);
//                    u[(2*node)+2-N]=(f[(2*node)+2-N]==1) ? 0 : ((LRU[0][BITS-1] == 1) ? 1 : 0);
                    u[(2*node)+2-N]=(f[(2*node)+2-N]) ? 0 : ((LRU[0][BITS-1]) ? 1 : 0);
                    g_calc(L_out[temp_index_f],L_out[temp_index_f+1],u[(2*node)+2-N],LRU[1]);
//                    u[(2*node)+3-N]=(f[(2*node)+3-N]==1) ? 0 : ((LRU[1][BITS-1] == 1) ? 1 : 0);
                    u[(2*node)+3-N]=(f[(2*node)+3-N]) ? 0 : ((LRU[1][BITS-1]) ? 1 : 0);
                    v_in[temp_index_f]=u[(2*node)+2-N] ^ u[(2*node)+3-N];
                    v_in[temp_index_f+1]=u[(2*node)+3-N];                                                       
                    
//                    if(node%2==1)
                    if(node[0])               
                        n_state = wait_R_logic;                                 
                    else                          
                        n_state=wait_U_logic;
                    end  
    wait_lnode_logic:  begin
                         depth=depth_reg+1; node=node_reg;
                         n_state=wait_lnode;
                       end                         
    wait_lnode:        begin
                         ena_L=0;wea_L=0;enb_L=1;
                         ena_v=0;wea_v=0; enb_v=0; 
                         n_state=state_lnode; 
                       end 
     state_lnode:      begin  
                         ena_L=0;wea_L=0;enb_L=0;
                         ena_v=1;wea_v=1; enb_v=0;
                         temp_index_f=((N/(2**(depth)))*((2*node+1)-((2**(depth))-1)));
 //                        temp_index_f=((N>>(2**(depth)))*((2*node+1)-((2**(depth))-1)));
                         fminsum_calc(L_out[temp_index_f],L_out[temp_index_f+1],LRU[0]);
//                         u[(2*node)+2-N]=(f[(2*node)+2-N]==1) ? 0 : ((LRU[0][BITS-1] == 1) ? 1 : 0);
                         u[(2*node)+2-N]=(f[(2*node)+2-N]) ? 0 : ((LRU[0][BITS-1]) ? 1 : 0);
                         g_calc(L_out[temp_index_f],L_out[temp_index_f+1],u[(2*node)+2-N],LRU[1]);
//                         u[(2*node)+3-N]=(f[(2*node)+3-N]==1) ? 0 : ((LRU[1][BITS-1] == 1) ? 1 : 0);   
                         u[(2*node)+3-N]=(f[(2*node)+3-N]) ? 0 : ((LRU[1][BITS-1]) ? 1 : 0);   
                         v_in[temp_index_f]=u[(2*node)+2-N] ^ u[(2*node)+3-N];
                         v_in[temp_index_f+1]=u[(2*node)+3-N];                                                    
                         n_state = wait_U_logic; 
                       end 
     wait_lstate_logic: begin
                         depth=depth_reg;  node=node_reg;
                         n_state=wait_lstate;
                        end                         
     wait_lstate:       begin
                          ena_L=0;wea_L=0;enb_L=1;
                          ena_v=0;wea_v=0; enb_v=0; 
                          n_state=state_last; 
                        end
     state_last:       begin
                          ena_L=0;wea_L=0;enb_L=0;
                          ena_v=1;wea_v=1; enb_v=0;
                          v=v_out;
                          n_state=idle;
                        end                                            
    endcase  
else    n_state = idle;                    
end
endmodule
*/


`timescale 1ns / 1ns
//////////////////////////////////////////////////////////////////////////////////
// Company: 
// Engineer: 
// 
// Create Date: 02/24/2021 08:03:07 PM
// Design Name: 
// Module Name: sc_decoder_fsm
// Project Name: 
// Target Devices: 
// Tool Versions: 
// Description: 
// 
// Dependencies: 
// 
// Revision:
// Revision 0.01 - File Created
// Additional Comments:
// 
//////////////////////////////////////////////////////////////////////////////////
`define BITS 8
module sc_decoder_fsm #(parameter BITS=8, N=11'd128)(
input clk, rst,
input in_valid,
input signed [N-1:0][BITS-1:0] y,
input [N-1:0]f, 
output wire [N-1:0]u_cap,
output wire [N-1:0]v_final,
output wire out_valid
);


//function for fminsum calculation
function void fminsum_calc;
        input signed [`BITS-1:0] a;
        input signed [`BITS-1:0] b;
       output signed [`BITS-1:0] c;
        
        logic [`BITS-2:0] abs_a;
        logic [`BITS-2:0] abs_b;
        logic [`BITS-2:0] abs_c;

        abs_a = (a[`BITS-1]) ? ~a[`BITS-2:0] + 1'b1 : a[`BITS-2:0];
        abs_b = (b[`BITS-1]) ? ~b[`BITS-2:0] + 1'b1 : b[`BITS-2:0];
        c[`BITS-1] = a[`BITS-1] ^ b[`BITS-1];
        abs_c = (abs_b < abs_a) ? abs_b : abs_a;
        c[`BITS-2:0] = (c[`BITS-1]) ? ~abs_c + 1'b1 : abs_c;
        
    endfunction
    
//function for g-value calculation
    function  void g_calc;
        input signed [`BITS-1:0] a;         
        input signed [`BITS-1:0] b;
        input u;
        output signed [`BITS:0] c;
        c = (u == 0) ? (b + a) : (b + (~a+1'b1));
    endfunction

//parameters and signals declarations
localparam d=$clog2(N);  //N=4, d=2(0 & 1)
//localparam n=2*N-1; //(2**d)-1;
//localparam cmax=0;
logic u[N];
logic [d:0]temp_index_f,temp_index_g;
reg signed [BITS-1:0] LRU[2];
reg [N-1:0]v;
logic [N-1:0][BITS-1:0]L_in, L_out;
logic [N-1:0]v_in, v_out;
logic ena_v,enb_v,wea_v;
logic ena_L,enb_L,wea_L;
//logic [1:0]counter,counter_reg;
logic [11:0]jL1,jL2,jR1,jR2,jR3,jU1,jU2;
logic [4:0] c_state, n_state;

//Auxiliary registers declarations
logic [d:0] depth,depth_reg;
logic [d:0] node,node_reg;
logic [11:0]tmp_L,tmp_L_reg, tmp_R,tmp_R_reg,tmp_U, tmp_U_reg;

//FSM States
localparam idle=5'd0, root=5'd1, wait_L_logic=5'd2, wait_L=5'd3, state_L=5'd4, wait_R_logic=5'd5, wait_R=5'd6, state_R=5'd7;
localparam wait_U_logic=5'd8, wait_U=5'd9, state_U=5'd10,wait_LRU_logic=5'd11, wait_LRU=5'd12, state_LRU=5'd13;
localparam wait_lnode_logic=5'd14, wait_lnode=5'd15, state_lnode=5'd16,wait_lstate_logic=5'd17, wait_lstate=5'd18, state_last=5'd19;

//BlockRAM Instantiations
 bram_v #(.ADDR_WIDTH(d-1),.DATA_WIDTH(N),.DEPTH(2**(d-1))) bram_v_i (
.clk(clk),.ena(ena_v),.enb(enb_v),
.addra(depth_reg-1),
.addrb(depth_reg),
.wea(wea_v),
.dia(v_in),
.dob(v_out)
);

bram_L #(.ADDR_WIDTH(d-1),.DATA_WIDTH(N*BITS),.DEPTH(2**(d-1)),.N(N)) bram_L_i (
.clk(clk),.ena(ena_L),.enb(enb_L),
.addra(depth_reg),
.addrb(depth_reg-1),
.wea(wea_L),
.dia(L_in),
.dob(L_out)
);

//output assignment
for(genvar i=0; i<N; i++)
 begin
 assign u_cap[i] = u[i];
 end
 assign v_final=v;
 assign out_valid=(n_state==state_lnode)?1'b1:1'b0;
// assign out_valid=(n_state==state_last)?1'b1:1'b0;
 

// Sequential Logic - FSM State and Data Registers
always_ff@(posedge clk) 
begin
    if(rst==1) 
    begin
        c_state <= idle;
        depth_reg<=0;
        node_reg<=0;
//        counter_reg<=0;
        tmp_L_reg<=0;
        tmp_R_reg<=0;
        tmp_U_reg<=0;
     end
    else 
    begin
        c_state <= n_state;
        depth_reg<=depth;
        node_reg<=node;
//        counter_reg<=counter;
        tmp_L_reg<=tmp_L;
        tmp_R_reg<=tmp_R;
        tmp_U_reg<=tmp_U;
    end
end

//Combinational Logic - FSM Next State Logic
always_comb 
begin  
  if(in_valid)
    case(c_state)
    idle:       begin 
                   depth=0; node=0;
                   //counter=0; 
                   tmp_L=0; tmp_R=0; tmp_U=0;
                   ena_L=0;wea_L=0;enb_L=0;
                   ena_v=0;wea_v=0; enb_v=0;
                    if(out_valid)
                        n_state=idle;
                    else
                        n_state=root;    
                end
          
    root:       begin
                  depth=depth_reg;node=node_reg;
                  ena_L=1'b1;wea_L=1'b1;enb_L=0;
                  ena_v=0;wea_v=0; enb_v=0;     
                  for(int k=0; k<N; k++)
                  L_in[k]=y[k];
                  n_state=wait_L_logic;
                end
   wait_L_logic: 
                begin
                 depth=depth_reg+1'b1; node=((2*node_reg)+1'b1); tmp_L=0;
                 ena_L=0;wea_L=0;enb_L=1'b1;
                 ena_v=0;wea_v=0; enb_v=0; 
                
                 n_state=wait_L;
                end
    wait_L:    begin
//                 if(counter==cmax) begin
//                  counter=counter_reg-cmax;
                  n_state=state_L; 
//                 end
//                 else
//                  counter=counter_reg+1;
               end
    state_L:    begin     
                    ena_L=1'b1;wea_L=1'b1;enb_L=0;
                    ena_v=0;wea_v=0; enb_v=0;
                    tmp_L=tmp_L_reg+1'b1;
                    temp_index_f=((N/(2**(depth+1'b1)))*((2*(node)+1'b1)-((2**(depth+1'b1))-1'b1))); 
                    jL1=(tmp_L_reg)+temp_index_f;
                    jL2=(tmp_L_reg)+temp_index_f+(N/(2**depth));
                    fminsum_calc(L_out[jL1],L_out[jL2],L_in[jL1]); 
                                                               
                    if(tmp_L< (N/(2**depth)))    
                        n_state=state_L;                 
                    else if(depth<d)
                        n_state=wait_L_logic;
                    else
                        n_state=wait_LRU_logic;
                end

     wait_R_logic: begin
                    depth=depth_reg-1'b1; node=node_reg+1'b1; tmp_R=0;
                    n_state=wait_R;
                   end                       
     wait_R:      begin
                    ena_L=0;wea_L=0;enb_L=1'b1;
                    ena_v=0;wea_v=0; enb_v=1'b1; 
//                    if(counter==cmax) begin
//                    counter=counter_reg-cmax;
                    n_state=state_R; 
//                    end
//                    else
//                    counter=counter_reg+1;
                 end                       
    
    state_R:    begin 
                   ena_L=1'b1;wea_L=1'b1;enb_L=0;
                   ena_v=0;wea_v=0; enb_v=0;
                   tmp_R=tmp_R_reg+1'b1;
                   temp_index_f=((N/(2**(depth+1'b1)))*((2*(node)+1'b1)-((2**(depth+1'b1))-1'b1)));
                   temp_index_g=((N/(2**(depth+1'b1)))*((2*(node-1'b1)+1'b1)-((2**(depth+1'b1))-1'b1)));
                   jR1=(tmp_R_reg)+temp_index_g;
                   jR2=(tmp_R_reg)+temp_index_g+(N/(2**depth));
                   jR3=(tmp_R_reg)+temp_index_f;
                   g_calc(L_out[jR1],L_out[jR2],v_out[jR1],L_in[jR3]);
                      
                   if(tmp_R< (N/(2**depth)))    
                       n_state=state_R;
                   else if(node==((2**d)-2)) 
                       n_state=wait_lnode_logic;
                   else if(depth==d)
                       n_state=wait_LRU_logic;
                   else 
                       n_state = wait_L_logic;                                               
               end                   
                            
     wait_U_logic: begin
//                     depth=depth_reg-1'b1; node=(node_reg-2)/2; tmp_U=0;
                     depth=depth_reg-1'b1; node=(node_reg-2)>>1; tmp_U=0;
                     n_state=wait_U;
                   end                       
     wait_U:     begin
                     ena_L=0;wea_L=0;enb_L=0;
                     ena_v=0;wea_v=0; enb_v=1'b1; 
//                     if(counter==cmax) begin
//                     counter=counter_reg-cmax;
                     n_state=state_U; 
//                     end
//                     else
//                     counter=counter_reg+1;
                 end                        
    state_U:    begin
                     ena_L=0;wea_L=0;enb_L=0;
                     ena_v=1'b1;wea_v=1'b1; enb_v=0;
                     tmp_U=tmp_U_reg+1'b1;
                     temp_index_f=((N/(2**(depth)))*((2*node+1'b1)-((2**(depth))-1'b1))); 
                     jU1=(tmp_U_reg)+temp_index_f;
                     jU2=(tmp_U_reg)+temp_index_f+(N/(2**(depth)));
                     v_in[jU1] = v_out[jU1] ^ v_out[jU2]; 
                     v_in[jU2] = v_out[jU2]; 
                                    
                     if(tmp_U<(N/(2**(depth)))) 
                         n_state=state_U;
                     else if(depth>0 && ~node[0])  
                         n_state = wait_U_logic;                          
                     else if(depth>0 && node!=0)
                         n_state=wait_R_logic;
                     else              
                         n_state=wait_lstate_logic;         
                  end 
    wait_LRU_logic: begin
//                     depth=depth_reg; node=(node_reg-1'b1)/2;
                     depth=depth_reg; node=(node_reg-1'b1)>>1;
                      n_state=wait_LRU;
                    end                         
    wait_LRU:   begin
                    ena_L=0;wea_L=0;enb_L=1'b1;
                    ena_v=0;wea_v=0; enb_v=0; 
//                    if(counter==cmax) begin
//                    counter=counter_reg-cmax;
                    n_state=state_LRU; 
//                    end
//                    else
//                    counter=counter_reg+1;
                end                                                            
 
    state_LRU:  begin
                    ena_L=0;wea_L=0;enb_L=0;
                    ena_v=1'b1;wea_v=1'b1; enb_v=0;
                    temp_index_f=((N/(2**(depth)))*((2*node+1'b1)-((2**(depth))-1'b1)));
                    fminsum_calc(L_out[temp_index_f],L_out[temp_index_f+1],LRU[0]);
//                    u[(2*node)+2-N]=(f[(2*node)+2-N]==1) ? 0 : ((LRU[0][BITS-1] == 1) ? 1 : 0);
                    u[(2*node)+2-N]=(f[(2*node)+2-N]) ? 0 : ((LRU[0][BITS-1]) ? 1 : 0);
                    g_calc(L_out[temp_index_f],L_out[temp_index_f+1],u[(2*node)+2-N],LRU[1]);
                    //u[(2*node)+3-N]=(f[(2*node)+3-N]==1) ? 0 : ((LRU[1][BITS-1] == 1) ? 1 : 0);
                    u[(2*node)+3-N]=(f[(2*node)+3-N]) ? 0 : ((LRU[1][BITS-1]) ? 1 : 0);
                    v_in[temp_index_f]=u[(2*node)+2-N] ^ u[(2*node)+3-N];
                    v_in[temp_index_f+1]=u[(2*node)+3-N];                                                       
                    
//                    if(node[0]==1)               
                    if(node[0])               
                        n_state = wait_R_logic;                                 
                    else                          
                        n_state=wait_U_logic;
                    end  
    wait_lnode_logic:  begin
                         depth=depth_reg+1'b1; node=node_reg;
                         n_state=wait_lnode;
                       end                         
    wait_lnode:        begin
                         ena_L=0;wea_L=0;enb_L=1'b1;
                         ena_v=0;wea_v=0; enb_v=0; 
//                         if(counter==cmax) begin
//                         counter=counter_reg-cmax;
                         n_state=state_lnode; 
//                         end
//                         else
//                         counter=counter_reg+1;
                       end 
     state_lnode:      begin  
                         ena_L=0;wea_L=0;enb_L=0;
                         ena_v=1'b1;wea_v=1'b1; enb_v=0;
                         temp_index_f=((N/(2**(depth)))*((2*node+1'b1)-((2**(depth))-1'b1)));
                         fminsum_calc(L_out[temp_index_f],L_out[temp_index_f+1],LRU[0]);
 //                        u[(2*node)+2-N]=(f[(2*node)+2-N]==1'b1) ? 0 : ((LRU[0][BITS-1] == 1'b1) ? 1'b1 : 0);
                         u[(2*node)+2-N]=(f[(2*node)+2-N]) ? 0 : ((LRU[0][BITS-1]) ? 1'b1 : 0);
                         g_calc(L_out[temp_index_f],L_out[temp_index_f+1],u[(2*node)+2-N],LRU[1]);
//                         u[(2*node)+3-N]=(f[(2*node)+3-N]==1'b1) ? 0 : ((LRU[1][BITS-1] == 1) ? 1'b1 : 0);   
                         u[(2*node)+3-N]=(f[(2*node)+3-N]) ? 0 : ((LRU[1][BITS-1]) ? 1'b1 : 0);   
                         v_in[temp_index_f]=u[(2*node)+2-N] ^ u[(2*node)+3-N];
                         v_in[temp_index_f+1]=u[(2*node)+3-N];                                                    
                         n_state = wait_U_logic; 
                       end 
     wait_lstate_logic: begin
                         depth=depth_reg;  node=node_reg;
                         n_state=wait_lstate;
                        end                         
     wait_lstate:       begin
                          ena_L=0;wea_L=0;enb_L=1'b1;
                          ena_v=0;wea_v=0; enb_v=0; 
//                          if(counter==cmax) begin
//                          counter=counter_reg-cmax;
                          n_state=state_last; 
//                          end
//                          else
//                          counter=counter_reg+1;
                        end
     state_last:       begin
                          ena_L=0;wea_L=0;enb_L=0;
                          ena_v=1'b1;wea_v=1'b1; enb_v=0;
                          v=v_out;
                          n_state=idle;
                        end                                            
    endcase  
else    n_state = idle;                    
end
endmodule