From 55c3e36b2367daf6b9b3f894fb6a65b6d6b18158 Mon Sep 17 00:00:00 2001
From: lonkaars <loek@pipeframe.xyz>
Date: Tue, 21 Feb 2023 14:21:33 +0100
Subject: PPU debugged and working (but with unwanted latches)

---
 basys3/basys3.srcs/ppu_sprite_bg.vhd    | 20 +++++++++++++++-----
 basys3/basys3.srcs/ppu_sprite_bg_tb.vhd | 25 +++++++++++++++++++++++--
 basys3/basys3.xpr                       |  8 +++++++-
 3 files changed, 45 insertions(+), 8 deletions(-)

diff --git a/basys3/basys3.srcs/ppu_sprite_bg.vhd b/basys3/basys3.srcs/ppu_sprite_bg.vhd
index a92c401..391083f 100644
--- a/basys3/basys3.srcs/ppu_sprite_bg.vhd
+++ b/basys3/basys3.srcs/ppu_sprite_bg.vhd
@@ -67,6 +67,8 @@ architecture Behavioral of ppu_sprite_bg is
 	signal TRANSFORM_YI, TRANSFORM_YO : std_logic_vector(PPU_SPRITE_POS_V_WIDTH-1 downto 0);
 	signal PIXEL_BIT_OFFSET : integer := 0;
 begin
+	-- TODO: fix latches
+
 	-- CIDX tri-state driver
 	CIDX <= O_CIDX when OE = '1' else (others => 'Z');
 
@@ -105,18 +107,26 @@ begin
 
 	-- TMM DATA
 	with PIXEL_BIT_OFFSET select
-		TMM_DATA_PAL_IDX <= TMM_DATA(2 downto 0) when 0,
-		                    TMM_DATA(5 downto 3) when 1,
-		                    TMM_DATA(8 downto 6) when 2,
-		                    TMM_DATA(11 downto 9) when 3,
-		                    TMM_DATA(14 downto 12) when 4,
+		TMM_DATA_PAL_IDX <= I_TMM_DATA(2 downto 0) when 0,
+		                    I_TMM_DATA(5 downto 3) when 1,
+		                    I_TMM_DATA(8 downto 6) when 2,
+		                    I_TMM_DATA(11 downto 9) when 3,
+		                    I_TMM_DATA(14 downto 12) when 4,
 		                    (others => '0') when others;
 
 	-- state machine (pipeline stage counter)
 	fsm: process(CLK, RESET)
 	begin
 		if RESET = '1' then
+			-- reset state
 			state <= PL_BAM_ADDR;
+			-- reset internal pipeline registers
+			-- O_BAM_ADDR <= (others => '0');
+			-- I_BAM_DATA <= (others => '0');
+			-- O_TMM_ADDR <= (others => '0');
+			-- I_TMM_DATA <= (others => '0');
+			-- reset working color register
+			-- O_CIDX <= (others => '0');
 		elsif rising_edge(CLK) then
 			state <= next_state;
 		end if;
diff --git a/basys3/basys3.srcs/ppu_sprite_bg_tb.vhd b/basys3/basys3.srcs/ppu_sprite_bg_tb.vhd
index 2dee2fe..65da15c 100644
--- a/basys3/basys3.srcs/ppu_sprite_bg_tb.vhd
+++ b/basys3/basys3.srcs/ppu_sprite_bg_tb.vhd
@@ -59,13 +59,34 @@ begin
 		TMM_DATA => TMM_DATA,
 		CIDX => CIDX);
 
-	BAM_DATA <= std_logic_vector(to_unsigned(16#4814#, PPU_BAM_DATA_WIDTH));  -- hex((1 << 14) | (0 << 13) | (2 << 10) | (20 << 0))
-	TMM_DATA <= std_logic_vector(to_unsigned(16#ffff#, PPU_TMM_DATA_WIDTH));
+	-- inputs
+	-- BAM_DATA -> FLIP_H + palette index 2 + tilemap index 10
+	-- TMM_DATA -> all pixels color 7
+	-- X -> 25
+	-- Y -> 60
+	-- BG_SHIFT_X -> 3
+	-- BG_SHIFT_Y -> 3
+	BAM_DATA <= 15x"4814"; -- hex((1 << 14) | (0 << 13) | (2 << 10) | (20 << 0))
+	TMM_DATA <= 15x"7e3f"; -- hex(0x7fff & ~(0b111 << 6))
 	X <= std_logic_vector(to_unsigned(25, PPU_POS_H_WIDTH));
 	Y <= std_logic_vector(to_unsigned(60, PPU_POS_V_WIDTH));
 	BG_SHIFT_X <= std_logic_vector(to_unsigned(3, PPU_POS_H_WIDTH));
 	BG_SHIFT_Y <= std_logic_vector(to_unsigned(3, PPU_POS_V_WIDTH));
 
+	-- expected outputs:
+	-- absolute pixel coordinates -> (28, 63)
+	-- absolute background canvas tile index coordinates -> (1, 3)
+	-- tile index -> 3 * 40 + 1 = 121
+	-- BAM_ADDR => 121 (OK)
+	-- sprite local coordinates -> (12, 15)
+	-- transformed local coordinates -> (12, 0) (apply FLIP_H)
+	-- pixel index -> 0 * 16 + 12 = 12
+	-- pixel word address -> 52 * 20 + 12//5 -> 1042
+	-- TMM_ADDR => 1042 (OK)
+	-- pixel bits -> [pixel n+] = 12 % 5 = 2 -> 8 downto 6
+	-- cidx should be -- (2 << 3) | (0 << 0) = 16
+	-- CIDX => 16 (OK)
+
 	tb : process
 	begin
 		for i in 0 to 32 loop
diff --git a/basys3/basys3.xpr b/basys3/basys3.xpr
index 556c73e..c79fd58 100644
--- a/basys3/basys3.xpr
+++ b/basys3/basys3.xpr
@@ -61,7 +61,7 @@
     <Option Name="IPStaticSourceDir" Val="$PIPUSERFILESDIR/ipstatic"/>
     <Option Name="EnableBDX" Val="FALSE"/>
     <Option Name="DSABoardId" Val="basys3"/>
-    <Option Name="WTXSimLaunchSim" Val="31"/>
+    <Option Name="WTXSimLaunchSim" Val="39"/>
     <Option Name="WTModelSimLaunchSim" Val="0"/>
     <Option Name="WTQuestaLaunchSim" Val="0"/>
     <Option Name="WTIesLaunchSim" Val="0"/>
@@ -217,6 +217,12 @@
           <Attr Name="UsedIn" Val="simulation"/>
         </FileInfo>
       </File>
+      <File Path="$PSRCDIR/ppu_sprite_transform_tb.vhd">
+        <FileInfo>
+          <Attr Name="UsedIn" Val="synthesis"/>
+          <Attr Name="UsedIn" Val="simulation"/>
+        </FileInfo>
+      </File>
       <Config>
         <Option Name="DesignMode" Val="RTL"/>
         <Option Name="TopModule" Val="ppu_sprite_bg_tb"/>
-- 
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