From dbeae12a715975ee6cfdbb2266dfcec1394b44c7 Mon Sep 17 00:00:00 2001
From: Alexander Oh <oh.a@gmx.at>
Date: Wed, 26 May 2010 01:25:27 +0200
Subject: [PATCH] Statemachine now returns to idle.

The state machine now is capable to stop dumping memory.
---
 src/pc_communication.vhd | 56 +++++++++++++++++++++-------------------
 1 file changed, 30 insertions(+), 26 deletions(-)

diff --git a/src/pc_communication.vhd b/src/pc_communication.vhd
index 44e43cd..4e2cc41 100644
--- a/src/pc_communication.vhd
+++ b/src/pc_communication.vhd
@@ -39,6 +39,7 @@ architecture beh of pc_communication is
 	signal new_i, new_i_next : std_logic;
 	signal tx_done_i, tx_done_i_next : std_logic;
 	signal d_done_i : std_logic;
+	signal s_done, s_done_next : std_logic;
 
 	signal char, char_next : hbyte;
 	signal char_en : std_logic;
@@ -68,6 +69,7 @@ begin
 			tx_data <= "00000000";
 			spalte_up <= '0';
 			tx_done_i <= '0';
+			s_done <= '0';
 		elsif rising_edge(sys_clk) then
 			push_history <= push_history_next;
 			spalte <= spalte_next;
@@ -77,35 +79,13 @@ begin
 			new_i <= new_i_next;
 			tx_done_i <= tx_done_i_next;
 			spalte_up <= spalte_up_next;
+			s_done <= s_done_next;
 			if (char_en = '1') then
 				char <= char_next;
 			end if;
 		end if;
 	end process sync;
 
-	process (spalte_up, spalte, zeile)
-	begin
-		if (spalte_up = '1') then
-			if (spalte > 72) then
-				if zeile + 1 > 50 then 
-					spalte_next <= 1;
-					zeile_next <= 1;
-					--done <= '1'; lets assume this false
-					assert false severity failure;
-				else
-					spalte_next <= 1;
-					zeile_next <= zeile + 1;
-				end if;
-			else
-				spalte_next <= spalte + 1; --overflow here!
-				zeile_next <= zeile;
-			end if;
-		else
-			spalte_next <= spalte;
-			zeile_next <= zeile;
-		end if;
-	end process;
-
 	async_push_history : process (rx_new, rx_data, btn_a)
 	begin
 		if rx_new = '1' then
@@ -121,11 +101,33 @@ begin
 		end if;
 	end process async_push_history;
 
-	output_pc : process (state, zeile, spalte, char, tx_done_i)
+	output_pc : process (state, zeile, spalte, char, tx_done_i, spalte_up, spalte, zeile)
 	begin
 		get_next <= '0';
 		new_i_next <= '0';
+
 		spalte_up_next <= '0';
+		s_done_next <= '0';
+		spalte_next <= spalte;
+		zeile_next <= zeile;
+
+		if (spalte_up = '1') then
+			if (spalte > 72) then
+				if zeile + 1 > 50 then 
+					spalte_next <= 1;
+					zeile_next <= 1;
+					s_done_next <= '1'; --lets assume this false
+					--assert false severity failure;
+				else
+					spalte_next <= 1;
+					zeile_next <= zeile + 1;
+				end if;
+			else
+				spalte_next <= spalte + 1; --overflow here!
+				zeile_next <= zeile;
+			end if;
+		end if;
+
 		case state is
 			when IDLE =>
 				null;
@@ -139,22 +141,24 @@ begin
 				if (tx_done_i = '1') then
 					spalte_up_next <= '1';
 				end if;
+
 			when DONE =>
 				null;
 		end case;
 	end process output_pc;
 
-	next_state_pc : process (rx_new, btn_a, d_done, tx_done_i)
+	next_state_pc : process (rx_new, btn_a, d_done, tx_done_i, s_done)
 	begin
 		case state is
 			when IDLE =>
 				if rx_new = '1' or btn_a = '1' then
 					state_next <= FETCH;
-					
 				end if;
 			when FETCH =>
 				if (d_done = '1') then
 					state_next <= FORWARD;
+				elsif (s_done = '1') then
+					state_next <= IDLE;
 				end if;
 			when FORWARD =>
 				if (tx_done_i = '1') then
-- 
2.25.1