From 1e35436b10d6c700a8f8160a5b8ae4ac7723e42b Mon Sep 17 00:00:00 2001
From: Andreas Olofsson <andreas@adapteva.com>
Date: Wed, 20 Jan 2016 17:14:55 -0500
Subject: [PATCH] Adding generic mesh packet mux

---
 emesh/hdl/emesh_mux.v | 79 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 79 insertions(+)
 create mode 100644 emesh/hdl/emesh_mux.v

diff --git a/emesh/hdl/emesh_mux.v b/emesh/hdl/emesh_mux.v
new file mode 100644
index 0000000..c2e5eed
--- /dev/null
+++ b/emesh/hdl/emesh_mux.v
@@ -0,0 +1,79 @@
+module emesh_mux (/*AUTOARG*/
+   // Outputs
+   wait_out, access_out, packet_out,
+   // Inputs
+   access_in, packet_in, wait_in
+   );
+   
+   //#####################################################################
+   //# PARAMETERS
+   //#####################################################################
+   parameter AW      = 32;
+   parameter PW      = 2 * AW + 40;   
+   parameter N       = 99; 
+   parameter CFG     = "STATIC"; //Arbitration configuration
+                                 //"STATIC" fixed priority
+                                 //"DYNAMIC" round robin priority
+
+   //#####################################################################
+   //# INTERFACE
+   //#####################################################################
+
+   //Incoming transaction
+   input [N-1:0]    access_in;
+   input [N*PW-1:0] packet_in;
+   output [N-1:0]   wait_out;
+
+   //Outgoing transaction
+   output 	    access_out;
+   output [PW-1:0]  packet_out;
+   input 	    wait_in;
+   
+   //#####################################################################
+   //# BODY
+   //#####################################################################
+   
+   //local variables
+   wire [N-1:0]     grants;
+   reg [PW-1:0]     packet_out;
+   integer 	    i;
+   
+   //arbiter
+   generate
+      if(CFG=="STATIC")		
+	begin
+	   oh_arbiter #(.N(N))
+	   arbiter(// Outputs
+		   .grants   (grants[N-1:0]),
+		   // Inputs
+		   .requests (access_in[N-1:0])
+		   );      
+	end
+      else if (CFG=="DYNAMIC")
+	begin
+	   initial
+	     $display("ROUND ROBIN ARBITER NOT IMPLEMENTED\n");	   
+	end
+   endgenerate
+   
+   //access signal
+   assign access_out = |(access_in[N-1:0]);
+
+   //raise wait signals 
+   assign wait_out[N-1:0] = access_in[N-1:0] & (~grants[N-1:0] | {(N){wait_in}});
+
+   //parametrized mux
+   always @*
+     begin
+	packet_out[PW-1:0] = 'b0;
+	for(i=0;i<N;i=i+1)
+	  packet_out[PW-1:0] |= {(PW){grants[i]}} & packet_in[((i+1)*PW-1)-:PW];
+     end
+
+endmodule // mesh_mux
+
+// Local Variables:
+// verilog-library-directories:("." "../../common/hdl")
+// End:
+
+