1 files changed, 58 insertions, 0 deletions
diff --git a/fpga/usrp2/sdr_lib/hb/mac.v b/fpga/usrp2/sdr_lib/hb/mac.v
new file mode 100644
index 000000000..5a270bc73
--- /dev/null
+++ b/fpga/usrp2/sdr_lib/hb/mac.v
@@ -0,0 +1,58 @@
+
+
+module mac (input clock, input reset, input enable, input clear,
+	    input signed [15:0] x, input signed [15:0] y,
+	    input [7:0] shift, output [15:0] z );
+
+   reg signed [30:0] product;
+   reg signed [39:0] z_int;
+   reg signed [15:0] z_shift;
+
+   reg enable_d1;
+   always @(posedge clock)
+     enable_d1 <= #1 enable;
+   
+   always @(posedge clock)
+     if(reset | clear)
+       z_int <= #1 40'd0;
+     else if(enable_d1)
+       z_int <= #1 z_int + {{9{product[30]}},product};
+
+   always @(posedge clock)
+     product <= #1 x*y;
+
+   always @*   // FIXME full case? parallel case?
+     case(shift)
+       //8'd0 : z_shift <= z_int[39:24];
+       //8'd1 : z_shift <= z_int[38:23];
+       //8'd2 : z_shift <= z_int[37:22];
+       //8'd3 : z_shift <= z_int[36:21];
+       //8'd4 : z_shift <= z_int[35:20];
+       //8'd5 : z_shift <= z_int[34:19];
+       8'd6 : z_shift <= z_int[33:18];
+       8'd7 : z_shift <= z_int[32:17];
+       8'd8 : z_shift <= z_int[31:16];
+       8'd9 : z_shift <= z_int[30:15];
+       8'd10 : z_shift <= z_int[29:14];
+       8'd11 : z_shift <= z_int[28:13];
+       //8'd12 : z_shift <= z_int[27:12];
+       //8'd13 : z_shift <= z_int[26:11];
+       //8'd14 : z_shift <= z_int[25:10];
+       //8'd15 : z_shift <= z_int[24:9];
+       //8'd16 : z_shift <= z_int[23:8];
+       //8'd17 : z_shift <= z_int[22:7];
+       //8'd18 : z_shift <= z_int[21:6];
+       //8'd19 : z_shift <= z_int[20:5];
+       //8'd20 : z_shift <= z_int[19:4];
+       //8'd21 : z_shift <= z_int[18:3];
+       //8'd22 : z_shift <= z_int[17:2];
+       //8'd23 : z_shift <= z_int[16:1];
+       //8'd24 : z_shift <= z_int[15:0];
+       default : z_shift <= z_int[15:0];
+     endcase // case(shift)
+   
+   // FIXME do we need to saturate?
+   //assign z = z_shift;
+   assign z = z_int[15:0];
+   
+endmodule // mac