aboutsummaryrefslogtreecommitdiffstats
path: root/fpga/usrp2/control_lib/wb_bridge_16_32.v
blob: 405e25c3c253864f05f05bae8a6f9a996a90a483 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
module wb_bridge_16_32
  #(parameter AWIDTH=16)
    (input wb_clk, input wb_rst,
     input A_cyc_i, input A_stb_i, input A_we_i, input [3:0] A_sel_i,
     input [AWIDTH-1:0] A_adr_i, input [31:0] A_dat_i, output [31:0] A_dat_o, output A_ack_o,
     output B_cyc_o, output B_stb_o, output B_we_o, output [1:0] B_sel_o,
     output [AWIDTH-1:0] B_adr_o, output [15:0] B_dat_o, input [15:0] B_dat_i, input B_ack_i
     );

   reg [15:0] 		 holding;
   reg 			 phase;
   
   assign 		 B_adr_o = {A_adr_i[AWIDTH-1:2],phase,1'b0};
   assign 		 B_cyc_o = A_cyc_i;
   assign 		 B_stb_o = A_stb_i;
   assign 		 B_we_o = A_we_i;

   assign 		 B_dat_o = ~phase ? A_dat_i[15:0] : A_dat_i[31:16];
   assign 		 B_sel_o = ~phase ? A_sel_i[1:0] : A_sel_i[3:2];

   assign 		 A_dat_o = {B_dat_i,holding};
   assign 		 A_ack_o = phase & B_ack_i;

   always @(posedge wb_clk)
     if(wb_rst)
       phase <= 0;
     else if(B_ack_i)
       phase <= ~phase;

   always @(posedge wb_clk)
     if(~phase & B_ack_i)
       holding <= B_dat_i;
   
endmodule // wb_bridge_16_32