Initial commit

Libs/Lcd/hdl/lcdCharacterEncoder_RTL.vhd

@@ -0,0 +1,213 @@
+library Common;
+  use Common.CommonLib.all;
+
+ARCHITECTURE Encoder OF lcdCharacterEncoder IS
+
+  constant lcdLineBitNb   : positive := 6;
+  constant lcdPageBitNb   : positive := 4;
+  constant lcdColumnBitNb : positive := 8;
+  
+
+  type fontDisplayStateType is (
+    init, idle, readChar, displayColumns
+  );
+  signal fontDisplayState   : fontDisplayStateType;
+
+  signal asciiColumnCounter : unsigned(requiredBitNb(fontColumnNb)-1 downto 0);
+  signal pixelOffset        : unsigned(requiredBitNb(fontColumnNb*fontRowNb-1)-1 downto 0);
+  
+  signal pageCounter        : unsigned(requiredBitNb(lcdPageNb)-1 downto 0);
+  signal columnCounter      : unsigned(requiredBitNb(lcdColumnNb)-1 downto 0);
+
+  signal A0                 : std_ulogic;
+  
+  signal pixelPage        : std_ulogic_vector(fontRowNb-1 downto 0);
+  signal pixelColumnHigh  : std_ulogic_vector(fontRowNb-1 downto 0);
+  signal pixelColumnLow   : std_ulogic_vector(fontRowNb-1 downto 0);
+  
+BEGIN
+  ------------------------------------------------------------------------------
+                                                                   -- diplay FSM
+  fontDisplaySequencer: process(reset, clock)
+  begin
+    if reset = '1' then
+      fontDisplayState <= init;
+    elsif rising_edge(clock) then
+      case fontDisplayState is
+        when init =>
+          if lcdBusy = '0' then
+            fontDisplayState <= idle;
+          end if;
+        when idle =>
+          if asciiSend = '1' then
+            fontDisplayState <= readChar;
+          end if;
+        when readChar =>
+          fontDisplayState <= displayColumns;
+        when displayColumns =>
+          if (asciiColumnCounter = 0) and (lcdBusy = '0') then
+            fontDisplayState <= idle;
+          end if;
+      end case;
+    end if;
+  end process fontDisplaySequencer;
+
+  asciiBusy <= '0' when fontDisplayState = idle
+    else '1';
+  
+  a0_proc: process(reset ,clock)
+  begin
+    if reset = '1' then
+      A0 <= '0';
+    elsif rising_edge(clock) then
+      if asciiSend = '1' then
+        if unsigned(asciiData) < 32 then
+          A0 <= '0';
+        else
+          A0 <= '1';
+        end if;
+      end if;
+    end if;
+  end process a0_proc;
+  
+
+  ------------------------------------------------------------------------------
+                                                         -- ascii column counter
+  asciiCountColums: process(reset, clock)
+  begin
+    if reset = '1' then
+      asciiColumnCounter <= (others => '0');
+    elsif rising_edge(clock) then
+      if asciiColumnCounter = 0 then
+        if (fontDisplayState = idle) and (asciiSend = '1') then
+          asciiColumnCounter <= asciiColumnCounter + 1;
+        end if;
+      else
+        if (fontDisplayState = displayColumns) and (lcdBusy = '0') then
+          if asciiColumnCounter < fontColumnNb then
+            asciiColumnCounter <= asciiColumnCounter + 1;
+          else
+            asciiColumnCounter <= (others => '0');
+          end if;
+        end if;
+      end if;
+    end if;
+  end process asciiCountColums;
+  ------------------------------------------------------------------------------
+                                                         -- page, column counter
+  counter: process(reset, clock)
+  begin
+    if reset = '1' then
+      pageCounter   <= (others => '0');
+      columnCounter <= (others => '0');
+      clearDisplay  <= '0';
+    elsif rising_edge(clock) then
+      clearDisplay <= '0';
+      if asciiSend = '1' then
+        case to_integer(unsigned(asciiData)) is
+          when 2 =>   -- Start of text (home)
+            pageCounter   <= (others => '0');
+            columnCounter <= (others => '0');
+          when 3 =>   -- End of text (end)
+            pageCounter   <= to_unsigned(lcdPageNb - 1,pageCounter'length);
+            columnCounter <= to_unsigned(lcdColumnNb - fontColumnNb, columnCounter'length);
+          when 8 =>    -- BS (backspace) (column back)
+            if (columnCounter - fontColumnNb) < 0 then
+              columnCounter <= (others => '0');
+            else
+              columnCounter <= columnCounter - fontColumnNb;
+            end if;
+          when 10 =>   -- LF (linefeed) (next line)
+            if pageCounter = (lcdPageNb-1) then
+              pageCounter   <= (others => '0');
+            else
+              pageCounter   <= pageCounter + 1;
+            end if;
+          when 11 =>   -- Vertical Tab (prev line)
+            if pageCounter = 0 then
+              pageCounter   <= to_unsigned(lcdPageNb - 1,pageCounter'length);
+            else
+              pageCounter   <= pageCounter - 1;
+            end if;
+          when 13 =>   -- CR (carriage return) (coloumn back)
+            columnCounter <= (others => '0');
+          when 24 =>   -- CAN (cancel) (clear display)
+            clearDisplay <= '1';
+          when others =>
+            if asciiData >= x"20" then -- normal ascii char
+              columnCounter <= columnCounter + fontColumnNb;
+            end if;
+        end case;
+      end if;
+    end if;
+  end process counter;
+
+  lcdSend <= '1' when
+      (fontDisplayState = displayColumns) and
+      (lcdBusy = '0') and
+      (asciiColumnCounter > 0)
+    else '0';
+  ------------------------------------------------------------------------------
+                                                                     -- Ram Data
+  pixelOffset <= resize(
+    resize(fontColumnNb-asciiColumnCounter, pixelOffset'length)*fontRowNb,
+    pixelOffset'length
+  ) when asciiColumnCounter > 0
+    else (others => '0');
+  pixelPage <= 
+    pixelData(
+      to_integer(pixelOffset) + fontRowNb-1 downto
+      to_integer(pixelOffset) + lcdPageBitNb
+    ) &
+    std_ulogic_vector(resize(pageCounter,lcdPageBitNb));
+  pixelColumnHigh <=
+    pixelData(
+      to_integer(pixelOffset) + fontRowNb-1 downto
+      to_integer(pixelOffset) + (lcdColumnBitNb/2)
+    ) &
+    std_ulogic_vector(columnCounter(
+      columnCounter'high downto (columnCounter'length/2)
+    ));
+  pixelColumnLow <=
+    pixelData(
+      to_integer(pixelOffset) + fontRowNb-1 downto
+      to_integer(pixelOffset) + (lcdColumnBitNb/2)
+    ) &
+    std_ulogic_vector(columnCounter(
+      (columnCounter'length/2)-1 downto columnCounter'low
+    ));
+
+  buildLcdData: process(
+    A0, pixelData, pixelOffset,
+    pixelPage, pixelColumnHigh, pixelColumnLow
+  )
+  begin
+    lcdData(lcdData'high) <= A0;
+    if A0 = '1' then
+      lcdData(lcdData'high-1 downto 0) <= pixelData(
+        to_integer(pixelOffset)+fontRowNb-1 downto to_integer(pixelOffset)
+      );
+    elsif pixelOffset >= 40 then
+      lcdData(lcdData'high-1 downto 0) <= pixelData(
+        to_integer(pixelOffset)+fontRowNb-1 downto to_integer(pixelOffset)
+      );
+    elsif pixelOffset >= 32 then
+      lcdData(lcdData'high-1 downto 0) <= pixelPage;
+    elsif pixelOffset >= 24 then
+      lcdData(lcdData'high-1 downto 0) <= pixelColumnHigh;
+    elsif pixelOffset >= 16 then
+      lcdData(lcdData'high-1 downto 0) <= pixelColumnLow;
+    else
+      lcdData(lcdData'high-1 downto 0) <= pixelData(
+        to_integer(pixelOffset)+fontRowNb-1 downto to_integer(pixelOffset)
+      );
+    end if;
+  end process buildLcdData;
+  --lcdData <= A0 & pixelData(to_integer(pixelOffset)+fontRowNb-1 downto to_integer(pixelOffset)) when (A0 = '1')
+  --      else A0 & pixelData(to_integer(pixelOffset)+fontRowNb-1 downto to_integer(pixelOffset)) when (pixelOffset >= 40)
+  --      else A0 & pixelPage                                   when (pixelOffset >= 32)
+  --      else A0 & pixelColumnHigh                                 when (pixelOffset >= 24)
+  --      else A0 & pixelColumnLow                                when (pixelOffset >= 16)
+  --      else A0 & pixelData(to_integer(pixelOffset)+fontRowNb-1 downto to_integer(pixelOffset));
+  
+END ARCHITECTURE Encoder;