module apb_bridge(
  apb_harb_hrdata,
  apb_harb_hready,
  apb_harb_hresp,
  apb_xx_paddr,
  apb_xx_penable,
  apb_xx_pwdata,
  apb_xx_pwrite,
  harb_apb_hsel,
  harb_xx_haddr,
  harb_xx_hwdata,
  harb_xx_hwrite,
  hclk,
  hrst_b,
  prdata_s1,
  prdata_s2,
  prdata_s3,
  prdata_s4,
  prdata_s5,
  prdata_s6,
  prdata_s7,
  psel_s1,
  psel_s2,
  psel_s3,
  psel_s4,
  psel_s5,
  psel_s6,
  psel_s7
);


input           harb_apb_hsel;  
input   [39:0]  harb_xx_haddr;  
input   [31:0]  harb_xx_hwdata; 
input           harb_xx_hwrite; 
input           hclk;           
input           hrst_b;         
input   [31:0]  prdata_s1;      
input   [31:0]  prdata_s2;      
input   [31:0]  prdata_s3;      
input   [31:0]  prdata_s4;      
input   [31:0]  prdata_s5;      
input   [31:0]  prdata_s6;      
input   [31:0]  prdata_s7;      
output  [31:0]  apb_harb_hrdata; 
output          apb_harb_hready; 
output  [1 :0]  apb_harb_hresp; 
output  [39:0]  apb_xx_paddr;   
output          apb_xx_penable; 
output  [31:0]  apb_xx_pwdata;  
output          apb_xx_pwrite;  
output          psel_s1;        
output          psel_s2;        
output          psel_s3;        
output          psel_s4;        
output          psel_s5;        
output          psel_s6;        
output          psel_s7;        


reg     [31:0]  apb_harb_hrdata; 
reg             apb_harb_hready; 
reg     [39:0]  apb_xx_paddr;   
reg             apb_xx_penable; 
reg             apb_xx_psel;    
reg     [31:0]  apb_xx_pwdata;  
reg             apb_xx_pwrite;  
reg     [2 :0]  cur_state;      
reg     [39:0]  haddr_latch;    
reg             hwrite_latch;   
reg     [2 :0]  nxt_state;      


wire    [1 :0]  apb_harb_hresp; 
wire            busy_s1;        
wire            busy_s2;        
wire            busy_s3;        
wire            busy_s4;        
wire            busy_s5;        
wire            busy_s6;        
wire            busy_s7;        
wire            busy_s8;        
wire            enable_latch;   
wire            enable_r_select; 
wire            harb_apb_hsel;  
wire    [39:0]  harb_xx_haddr;  
wire    [31:0]  harb_xx_hwdata; 
wire            harb_xx_hwrite; 
wire            hclk;           
wire            hrst_b;         
wire            idle_latch;     
wire            idle_r_select;  
wire    [31:0]  prdata_s1;      
wire    [31:0]  prdata_s2;      
wire    [31:0]  prdata_s3;      
wire    [31:0]  prdata_s4;      
wire    [31:0]  prdata_s5;      
wire    [31:0]  prdata_s6;      
wire    [31:0]  prdata_s7;      
wire            psel_s1;        
wire            psel_s2;        
wire            psel_s3;        
wire            psel_s4;        
wire            psel_s5;        
wire            psel_s6;        
wire            psel_s7;        
wire            psel_s8;        



assign apb_harb_hresp[1:0] = 2'b0;


parameter IDLE     = 3'b000;
parameter LATCH    = 3'b001;
parameter W_SELECT = 3'b010;
parameter R_SELECT = 3'b011;
parameter ENABLE   = 3'b100;

always @(posedge hclk or negedge hrst_b)
begin
  if(!hrst_b) 
  begin
    cur_state[2:0] <= IDLE;
  end
  else 
  begin
    cur_state[2:0] <= nxt_state[2:0];
  end
end

assign idle_latch       = harb_apb_hsel && harb_xx_hwrite;
assign idle_r_select    = harb_apb_hsel && !harb_xx_hwrite;
assign enable_latch     = harb_apb_hsel && harb_xx_hwrite;
assign enable_r_select  = harb_apb_hsel && !harb_xx_hwrite;


always @( enable_r_select
       or idle_latch
       or idle_r_select
       or enable_latch
       or cur_state[2:0])
begin
nxt_state[2:0] = IDLE;
case(cur_state[2:0])
  IDLE: 
  begin
    if(idle_latch) 
    begin
      nxt_state[2:0] = LATCH;
    end
    else if(idle_r_select)
    begin
      nxt_state[2:0] = R_SELECT;
    end
    else
    begin
      nxt_state[2:0] = IDLE;
    end
  end
  LATCH: 
  begin
    nxt_state[2:0] = W_SELECT;
  end
  W_SELECT: 
  begin
    nxt_state[2:0] = ENABLE;
  end
  R_SELECT: 
  begin
    nxt_state[2:0] = ENABLE;
  end
  ENABLE: 
  begin
    if(enable_latch) 
    begin
      nxt_state[2:0] = LATCH;
    end
    else if(enable_r_select)
    begin
      nxt_state[2:0] = R_SELECT;
    end
    else
    begin
      nxt_state[2:0] = IDLE;
    end
  end
endcase

end


always @(posedge hclk or negedge hrst_b)
begin
  if(!hrst_b) 
  begin
    haddr_latch[39:0]  <= 40'b0;
    hwrite_latch       <= 1'b0;
  end
  else if(nxt_state[2:0]==LATCH) 
  begin
    haddr_latch[39:0] <= harb_xx_haddr[39:0];
    hwrite_latch      <= harb_xx_hwrite;
  end
  else 
  begin
    haddr_latch[39:0] <= haddr_latch[39:0];
    hwrite_latch      <= hwrite_latch;
  end
end

always @(posedge hclk or negedge hrst_b)
begin
  if(!hrst_b) 
  begin
    apb_xx_paddr[39:0]  <= 40'b0;
    apb_xx_pwrite       <= 1'b0;
  end
  else if(nxt_state[2:0]==W_SELECT) 
  begin
    apb_xx_paddr[39:0]  <= haddr_latch[39:0];
    apb_xx_pwrite       <= hwrite_latch;
  end
  else if(nxt_state[2:0]==R_SELECT) 
  begin
    apb_xx_paddr[39:0]  <= harb_xx_haddr[39:0];
    apb_xx_pwrite       <= harb_xx_hwrite;
  end
  else 
  begin
    apb_xx_paddr[39:0]  <= apb_xx_paddr[39:0];
    apb_xx_pwrite       <= apb_xx_pwrite;
  end
end

always @(posedge hclk or negedge hrst_b)
begin
  if(!hrst_b) 
  begin
    apb_xx_pwdata[31:0] <= 32'b0;
  end
  else if(nxt_state[2:0]==W_SELECT) 
  begin
    apb_xx_pwdata[31:0] <= harb_xx_hwdata[31:0];
  end
  else 
  begin
    apb_xx_pwdata[31:0] <= apb_xx_pwdata[31:0];
  end
end

always @(posedge hclk or negedge hrst_b)
begin
  if(!hrst_b)
  begin
    apb_xx_psel <= 1'b0;
  end
  else if(nxt_state[2:0]==W_SELECT)
  begin
    apb_xx_psel <= 1'b1;
  end
  else if(nxt_state[2:0]==R_SELECT)
  begin
    apb_xx_psel <= 1'b1;
  end
  else if(nxt_state[2:0]==ENABLE)
  begin
    apb_xx_psel <= 1'b1;
  end
  else
  begin
    apb_xx_psel <= 1'b0;
  end
end

always @(posedge hclk or negedge hrst_b)
begin
  if(!hrst_b)
  begin
    apb_xx_penable <= 1'b0;
  end
  else if(nxt_state[2:0]==ENABLE)
  begin
    apb_xx_penable <= 1'b1;
  end
  else
  begin
    apb_xx_penable <= 1'b0;
  end
end

always @(posedge hclk or negedge hrst_b)
begin
  if(!hrst_b)
  begin
    apb_harb_hready <= 1'b1;
  end
  else if(nxt_state[2:0]==LATCH)
  begin
    apb_harb_hready <= 1'b0;
  end
  else if(nxt_state[2:0]==W_SELECT)
  begin
    apb_harb_hready <= 1'b0;
  end
  else if(nxt_state[2:0]==R_SELECT)
  begin
    apb_harb_hready <= 1'b0;
  end
  else
  begin
    apb_harb_hready <= 1'b1;
  end
end


assign psel_s1 = apb_xx_psel && (apb_xx_paddr>=`PS1_BASE_START) && (apb_xx_paddr<=`PS1_BASE_END);
assign psel_s2 = apb_xx_psel && (apb_xx_paddr>=`PS2_BASE_START) && (apb_xx_paddr<=`PS2_BASE_END);
assign psel_s3 = apb_xx_psel && (apb_xx_paddr>=`PS3_BASE_START) && (apb_xx_paddr<=`PS3_BASE_END);
assign psel_s4 = apb_xx_psel && (apb_xx_paddr>=`PS4_BASE_START) && (apb_xx_paddr<=`PS4_BASE_END);
assign psel_s5 = apb_xx_psel && (apb_xx_paddr>=`PS5_BASE_START) && (apb_xx_paddr<=`PS5_BASE_END);
assign psel_s6 = apb_xx_psel && (apb_xx_paddr>=`PS6_BASE_START) && (apb_xx_paddr<=`PS6_BASE_END);
assign psel_s7 = apb_xx_psel && (apb_xx_paddr>=`PS7_BASE_START) && (apb_xx_paddr<=`PS7_BASE_END);
assign psel_s8 = apb_xx_psel && (apb_xx_paddr>=`PS8_BASE_START) && (apb_xx_paddr<=`PS8_BASE_END);















assign busy_s1 = apb_xx_penable && psel_s1;
assign busy_s2 = apb_xx_penable && psel_s2;
assign busy_s3 = apb_xx_penable && psel_s3;
assign busy_s4 = apb_xx_penable && psel_s4;
assign busy_s5 = apb_xx_penable && psel_s5;
assign busy_s6 = apb_xx_penable && psel_s6;
assign busy_s7 = apb_xx_penable && psel_s7;
assign busy_s8 = apb_xx_penable && psel_s8;


always @( busy_s3
       or busy_s4
       or busy_s7
       or busy_s2
       or prdata_s5[31:0]
       or busy_s6
       or prdata_s6[31:0]
       or busy_s5
       or busy_s1
       or prdata_s1[31:0]
       or busy_s8
       or prdata_s4[31:0]
       or prdata_s2[31:0]
       or prdata_s3[31:0]
       or prdata_s7[31:0])
begin
case({busy_s1,busy_s2,busy_s3,busy_s4,busy_s5,busy_s6,busy_s7,busy_s8})
  8'b10000000:
  begin
    apb_harb_hrdata[31:0] = prdata_s1[31:0] ;
  end
  8'b01000000:
  begin
    apb_harb_hrdata[31:0]  = prdata_s2[31:0] ;
  end
  8'b00100000:
  begin
    apb_harb_hrdata[31:0]  = prdata_s3[31:0] ;
  end
  8'b00010000:
  begin
    apb_harb_hrdata[31:0]  = prdata_s4[31:0] ;
  end
  8'b00001000:
  begin
    apb_harb_hrdata[31:0]  = prdata_s5[31:0] ;
  end
  8'b00000100:
  begin
    apb_harb_hrdata[31:0]  = prdata_s6[31:0];
  end
  8'b00000010:
  begin
    apb_harb_hrdata[31:0]  = prdata_s7[31:0] ;
  end
  8'b00000001:
  begin
    apb_harb_hrdata[31:0]  = 32'h0 ;
  end
  default:
  begin
    apb_harb_hrdata[31:0]  = 32'b0;
  end
endcase

end


endmodule