From 7bc3b662ab5065aba64dce26ad2ec41a0fdfb848 Mon Sep 17 00:00:00 2001
From: Andreas Olofsson <andreas@adapteva.com>
Date: Fri, 17 Apr 2015 15:49:58 -0400
Subject: [PATCH] Added profull HACK to async_fifo -this module needs rework
 -needs to have same capabilities as standard FPGA async fifos -remove this
 later

---
 memory/hdl/fifo_async.v       |  6 ++++--
 memory/hdl/fifo_async_emesh.v | 12 +++++++++---
 memory/hdl/fifo_full_block.v  | 25 +++++++++++++++++++++++--
 3 files changed, 36 insertions(+), 7 deletions(-)

diff --git a/memory/hdl/fifo_async.v b/memory/hdl/fifo_async.v
index c94e1eb..c85283b 100644
--- a/memory/hdl/fifo_async.v
+++ b/memory/hdl/fifo_async.v
@@ -2,7 +2,7 @@
 module fifo_async 
    (/*AUTOARG*/
    // Outputs
-   rd_data, rd_fifo_empty, wr_fifo_full,
+   rd_data, rd_fifo_empty, wr_fifo_full, wr_fifo_progfull,
    // Inputs
    reset, wr_clk, rd_clk, wr_write, wr_data, rd_read
    );
@@ -27,6 +27,7 @@ module fifo_async
    output [DW-1:0] rd_data;
    output          rd_fifo_empty;
    output          wr_fifo_full;
+   output          wr_fifo_progfull;
 
    //Wires
    wire [DW/8-1:0] wr_en;
@@ -67,7 +68,8 @@ module fifo_async
    //Write State Machine
    fifo_full_block #(.AW(AW)) fifo_full_block(
 					      // Outputs
-					      .wr_fifo_full	(wr_fifo_full),
+					      .wr_fifo_progfull	(wr_fifo_progfull),
+					      .wr_fifo_full	(wr_fifo_full),					      
 					      .wr_addr		(wr_addr[AW-1:0]),
 					      .wr_gray_pointer	(wr_gray_pointer[AW:0]),
 					      // Inputs
diff --git a/memory/hdl/fifo_async_emesh.v b/memory/hdl/fifo_async_emesh.v
index a432a4c..9b600ce 100644
--- a/memory/hdl/fifo_async_emesh.v
+++ b/memory/hdl/fifo_async_emesh.v
@@ -83,10 +83,16 @@ module fifo_async_emesh (/*AUTOARG*/
 					);
    
 `elsif TARGET_CLEAN
+
+   wire 	 tmp_progfull;    
+   assign fifo_progfull = tmp_progfull | fifo_full;//HACK, need to fix this
+   
+
   fifo_async #(.DW(104), .AW(5))  fifo_async (
-					.rd_data	(fifo_dout[103:0]),
-					.wr_fifo_full	(fifo_progfull),
-					.rd_fifo_empty	(fifo_empty),
+					.rd_data	  (fifo_dout[103:0]),
+					.wr_fifo_progfull (tmp_progfull),
+					.wr_fifo_full	  (fifo_full),
+					.rd_fifo_empty	  (fifo_empty),
 					//inputs
 					.reset		(reset),
 					.wr_clk		(wr_clk),
diff --git a/memory/hdl/fifo_full_block.v b/memory/hdl/fifo_full_block.v
index 0dc8163..69a533e 100644
--- a/memory/hdl/fifo_full_block.v
+++ b/memory/hdl/fifo_full_block.v
@@ -18,7 +18,7 @@
 */
 module fifo_full_block (/*AUTOARG*/
    // Outputs
-   wr_fifo_full, wr_addr, wr_gray_pointer,
+   wr_fifo_full, wr_fifo_progfull, wr_addr, wr_gray_pointer,
    // Inputs
    reset, wr_clk, wr_rd_gray_pointer, wr_write
    );
@@ -38,6 +38,9 @@ module fifo_full_block (/*AUTOARG*/
    //# OUTPUTS
    //###########
    output           wr_fifo_full;
+   output           wr_fifo_progfull;//TODO: hack!, fix this properly
+                                     //also make, programmable
+   
    output [AW-1:0]  wr_addr;
    output [AW:0]    wr_gray_pointer;//for read domain
 
@@ -55,6 +58,9 @@ module fifo_full_block (/*AUTOARG*/
    wire [AW:0]     wr_gray_next;
    wire [AW:0]     wr_binary_next;
    
+   wire 	   wr_fifo_progfull_next;
+   reg 		   wr_fifo_progfull;
+   
    //Counter States
    always @(posedge wr_clk or posedge reset)
      if(reset)
@@ -85,6 +91,15 @@ module fifo_full_block (/*AUTOARG*/
 			 (wr_gray_next[AW]     ^  wr_rd_gray_pointer[AW])     &
 			 (wr_gray_next[AW-1]   ^  wr_rd_gray_pointer[AW-1]);
 
+ 
+
+   //FIFO almost full
+   assign wr_fifo_progfull_next =
+			 (wr_gray_next[AW-3:0] == wr_rd_gray_pointer[AW-3:0]) &
+			 (wr_gray_next[AW]     ^  wr_rd_gray_pointer[AW])     &
+			 (wr_gray_next[AW-1]   ^  wr_rd_gray_pointer[AW-1])   &
+			 (wr_gray_next[AW-2]   ^  wr_rd_gray_pointer[AW-2]);
+
    always @ (posedge wr_clk or posedge reset)
      if(reset)
        wr_fifo_full <= 1'b0;
@@ -92,7 +107,13 @@ module fifo_full_block (/*AUTOARG*/
        wr_fifo_full <=wr_fifo_full_next;
 
 
+   always @ (posedge wr_clk or posedge reset)
+     if(reset)
+       wr_fifo_progfull <= 1'b0;
+     else
+       wr_fifo_progfull <=wr_fifo_progfull_next;
+
 endmodule // fifo_full_block
 
    
-		 
\ No newline at end of file
+