X-Git-Url: http://git.ieval.ro/?a=blobdiff_plain;f=reader.v;h=50cee43a0b9b34c0f7910620eb2affdc93dc9e23;hb=HEAD;hp=88e52e71bcf730f7c8a6652304585a64b20271ae;hpb=62e5ccb8304550f88f658af70a683936d47c08b2;p=clump.git

diff --git a/reader.v b/reader.v
index 88e52e7..50cee43 100644
--- a/reader.v
+++ b/reader.v
@@ -1,25 +1,26 @@
-`define STATE_IDLE    2'd0
-`define STATE_LENGTH  2'd1
-`define STATE_READ1   2'd2
-`define STATE_READ2   2'd3
+`define STATE_IDLE     3'd0
+`define STATE_LENGTH   3'd1
+`define STATE_READ1    3'd2
+`define STATE_READ2    3'd3
+`define STATE_WRITE    3'd4
+`define STATE_FINISHED 3'd5
 
-module READER (input clk, input clk_enable, input [7:0] rx_byte, input rx_signal, output reg finished = 0, output reg ram_we, output [12:0] ram_addr, output reg [15:0] ram_di);
-   reg [1:0] state = `STATE_IDLE;
+module READER (input clk, input clk_enable, input [7:0] rx_byte, input rx_signal, output finished, output ram_we, output [12:0] ram_addr, output reg [15:0] ram_di);
+   reg [2:0] state = `STATE_IDLE;
 
-   reg [12:0] words_left;
+   reg [12:0] total_words;
    reg [12:0] current_index;
 
    assign ram_addr = current_index;
+   assign finished = state == `STATE_FINISHED;
+   assign ram_we   = state == `STATE_WRITE;
 
    always @ (posedge clk)
 	 if (clk_enable) begin
-		if(!rx_signal) ram_we <= 0;
-
 		case(state)
 		  `STATE_IDLE: begin
 			 if(rx_signal) begin
-				words_left[12:8] <= rx_byte[4:0];
-				words_left[7:0] <= 0;
+				total_words[12:8] <= rx_byte[4:0];
 				current_index <= -1;
 				state <= `STATE_LENGTH;
 			 end
@@ -27,7 +28,7 @@ module READER (input clk, input clk_enable, input [7:0] rx_byte, input rx_signal
 
 		  `STATE_LENGTH: begin
 			 if(rx_signal) begin
-				words_left[7:0] <= rx_byte;
+				total_words[7:0] <= rx_byte;
 				state <= `STATE_READ1;
 			 end
 		  end
@@ -36,7 +37,6 @@ module READER (input clk, input clk_enable, input [7:0] rx_byte, input rx_signal
 			 if(rx_signal) begin
 				ram_di[15:8] <= rx_byte;
 				current_index <= current_index + 1;
-				words_left <= words_left - 1;
 				state <= `STATE_READ2;
 			 end
 		  end
@@ -44,17 +44,20 @@ module READER (input clk, input clk_enable, input [7:0] rx_byte, input rx_signal
 		  `STATE_READ2: begin
 			 if(rx_signal) begin
 				ram_di[7:0] <= rx_byte;
-				ram_we <= 1;
-				if(|words_left) begin
-				   state <= `STATE_READ1;
-				end else begin
-				   state <= `STATE_IDLE;
-				   finished <= 1;
-				end
+				state <= `STATE_WRITE;
+			 end
+		  end
+
+		  `STATE_WRITE: begin
+			 if(current_index + 1 == total_words) begin
+				state <= `STATE_FINISHED;
+			 end else begin
+				state <= `STATE_READ1;
 			 end
 		  end
+
+		  `STATE_FINISHED: state <= `STATE_IDLE;
+		  default:         state <= `STATE_IDLE;
 		endcase
 	 end // if (clk_enable)
-	 else
-	   finished <= 0;
 endmodule