From a7870ac9de65055a612623dc2b4fae9e12382d67 Mon Sep 17 00:00:00 2001
From: "Andreas.Olofsson" <andreas@adapteva.com>
Date: Wed, 22 Apr 2020 23:15:12 -0400
Subject: [PATCH] Cleaned up counter -Not functional

---
 common/hdl/oh_counter.v | 71 ++++++++++++++---------------------------
 1 file changed, 24 insertions(+), 47 deletions(-)

diff --git a/common/hdl/oh_counter.v b/common/hdl/oh_counter.v
index c405735..e13c7f2 100644
--- a/common/hdl/oh_counter.v
+++ b/common/hdl/oh_counter.v
@@ -1,68 +1,45 @@
 //#############################################################################
-//# Function: Binary to gray encoder                                          #
+//# Function: Generic counter                                                 #
 //#############################################################################
 //# Author:   Andreas Olofsson                                                #
 //# License:  MIT (see LICENSE file in OH! repository)                        # 
 //#############################################################################
 
-module oh_counter #(parameter DW   = 32,         // width of data inputs
-		    parameter TYPE = "INCREMENT" // also DECREMENT, GRAY, LFSR
+module oh_counter #(parameter DW   = 32  // width of data inputs
 		    ) 
    (
-   input 	   clk, // clk input
-   input 	   in, // input to count
-   input 	   en, // enable counter
-   input 	   load, // load counter
-   input [DW-1:0]  load_data,// load data
-   output [DW-1:0] count, // current count value   
-   output 	   carry, // carry out from counter
-   output 	   zero   // counter is zero
+    //inputs
+    input 	    clk, // clk input
+    input 	    in, // input to count
+    input 	    en, // enable counter
+    input 	    dir,//0=increment, 1=decrement
+    input 	    autowrap, //auto wrap around
+    input 	    load, // load counter
+    input [DW-1:0]  load_data, // input data to load
+    //outputs
+    output [DW-1:0] count, // count value
+    output 	    wraparund // wraparound indicator
     );
    
    // local variables
    reg [DW-1:0]    count;
-   reg 		   carry;
    wire [DW-1:0]   count_in;
-   wire 	   carry_in;
    
-   // configure counter based on type
-   generate
-      if(TYPE=="INCREMENT")
-	begin
-	   assign {carry_in,count_in[DW-1:0]} = count[DW-1:0] + in;
-	end
-      else if(TYPE=="DECREMENT")
-	begin
-	   assign count_in[DW-1:0] = count[DW-1:0] + in;
-	end
-      else if (TYPE=="GRAY")
-	begin
-	   initial
-	     $display ("NOT IMPLEMENTED");	   
-	end
-      else if (TYPE=="LFSR")
-	begin
-	   initial
-	     $display ("NOT IMPLEMENTED");	   
-	end      
-   endgenerate
-
+   //Select count direction
+   assign count_in[DW-1:0] = dir ? count[DW-1:0] - in :
+			           count[DW-1:0] + in ;
+   
    // counter
    always @(posedge clk)
      if(load)
-       begin
-	  carry         <= 1'b0;	  
-	  count[DW-1:0] <= load_data[DW-1:0];
-       end
-     else if (en)
-       begin
-	  carry         <= carry_in;
-	  count[DW-1:0] <= count_in[DW-1:0];
-       end
-
+       count[DW-1:0] <= load_data[DW-1:0];
+     else if (en & ~(wraparound & ~autowrap))
+       count[DW-1:0] <= count_in[DW-1:0];
+   
    // counter expired
-   assign zero = ~(count[DW-1:0]);
-      
+   assign wraparound = (dir & en & ~(|count[DW-1:0])) |
+		       (~dir & en & (&count[DW-1:0]));
+   
 endmodule // oh_counter