Add scrolling program

soc/lib/config.vhd

@@ -29,7 +29,7 @@ package config is
 	constant CFG_LED : integer := CFG_DMEM+1;
 	constant CFG_SW : integer := CFG_LED+1;
 	constant CFG_TIMER : integer := CFG_SW+1;
-    constant CFG_SEG : integer := CFG_TIMER+1;
+    constant CFG_SCR : integer := CFG_TIMER+1;
 
 -----------------------------
 -- base address (BADR) & mask address (MADR)

soc/peripheral/scrolling_buffer.vhd

@@ -52,6 +52,7 @@ begin
                     end if;
                 elsif buffer_clear = '1' then
                     ptr_last <= -1;
+                    ptr_write <= 0;
                 end if;
             end if;
 		end if;
@@ -65,17 +66,21 @@ begin
                 hex_char <= (others => '0');
             else
                 hex_char <= (others => '0');
-            
-                if next_char = '1' then
-                    if ptr_last = -1 then -- Special case
-                        hex_char <= (others => '0');
-                    else
-                        hex_char <= ring_buffer(ptr_read);
-
-                        if ptr_read = ptr_last then
-                            ptr_read <= 0;
+                
+                if buffer_clear = '1' then
+                    ptr_read <= 0;
+                else
+                    if next_char = '1' then
+                        if ptr_last = -1 then -- Special case
+                            hex_char <= (others => '0');
                         else
-                            ptr_read <= ptr_read + 1;
+                            hex_char <= ring_buffer(ptr_read);
+    
+                            if ptr_read = ptr_last then
+                                ptr_read <= 0;
+                            else
+                                ptr_read <= ptr_read + 1;
+                            end if;
                         end if;
                     end if;
                 end if;

soc/testbench/warmup4.vhd

@@ -0,0 +1,65 @@
+-- See the file "LICENSE" for the full license governing this code. --
+LIBRARY ieee;
+USE ieee.std_logic_1164.ALL;
+USE ieee.numeric_std.ALL;
+
+ENTITY warmup4_tb IS
+END ENTITY;
+
+ARCHITECTURE sim OF warmup4_tb IS
+
+	constant CLK_PERIOD : time := 10 ns;
+
+	signal clk 	: std_logic := '0';
+	signal rst	: std_logic;
+
+	signal led	: std_logic_vector(7 downto 0);
+    signal btn : std_logic_vector(4 downto 0) := (others => '0');
+    signal sw : std_logic_vector(15 downto 0) := (others => '0');
+    signal anodes : std_logic_vector(7 downto 0);
+    signal cathodes : std_logic_vector(7 downto 0);
+
+	COMPONENT lt16soc_top IS
+		generic(
+			programfilename : string := "../../programs/scrolling.ram"
+		);
+		port(
+			clk		: in  std_logic;
+			rst		: in std_logic;
+			led		: out std_logic_vector(7 downto 0);
+			btn : in std_logic_vector(4 downto 0);
+	        sw : in std_logic_vector(15 downto 0);
+            anodes : out std_logic_vector(7 downto 0);
+            cathodes : out std_logic_vector(7 downto 0)
+		);
+	END COMPONENT;
+
+BEGIN
+
+	dut: lt16soc_top port map(
+		clk=>clk,
+		rst=>rst,
+		led=>led,
+		btn=>btn,
+		sw=>sw,
+        anodes=>anodes,
+        cathodes=>cathodes
+	);
+
+	clk_gen: process
+	begin
+		clk	<= not clk;
+		wait for CLK_PERIOD/2;
+	end process clk_gen;
+
+	stimuli: process
+	begin
+		rst	<= '0';
+		wait for CLK_PERIOD;
+		rst	<= '1';
+		wait for 2ms;
+		assert false report "Simulation terminated!" severity failure;
+	end process stimuli;
+
+
+END ARCHITECTURE;

soc/top/top.vhd

@@ -204,16 +204,16 @@ begin
 		clk,rst_gen,slvi(CFG_TIMER),slvo(CFG_TIMER), irq_lines(3)
 	);
 	
-    segmentdev : wb_segment_adv
+    scrollingdev : wb_scrolling
 		generic map(
-			memaddr		=> CFG_BADR_SEG,
-			addrmask	=> CFG_MADR_SEG
+			memaddr		=> CFG_BADR_SCR,
+			addrmask	=> CFG_MADR_SCR
 		)
 		port map(
 			clk		=> clk,
 			rst		=> rst_gen,
-			wslvi	=> slvi(CFG_SEG),
-			wslvo	=> slvo(CFG_SEG),
+			wslvi	=> slvi(CFG_SCR),
+			wslvo	=> slvo(CFG_SCR),
 
             anodes => anodes,
             cathodes => cathodes