added state machine to enable cfg flash

diff --git a/machxo3/flash/generic_flash_ctrl.vhd b/machxo3/flash/generic_flash_ctrl.vhd
index 8ff6efad2b00b3a83b0d020ca099b263f068d0b4..0e2bcc8e87e88bf6905c43ba6b211821ab95c54f 100644 (file)
--- a/machxo3/flash/generic_flash_ctrl.vhd
+++ b/machxo3/flash/generic_flash_ctrl.vhd
@@ -143,7 +143,7 @@ architecture arch of generic_flash_ctrl is
   signal ram_addr_i  : std_logic_vector(3 downto 0);
   signal spi_ram_addr_i  : std_logic_vector(3 downto 0);
   
-  signal enable_cfg_flash : std_logic;
+  signal enable_cfg_flash : std_logic_vector(2 downto 0);
   signal testreg : std_logic_vector(DATA_BUS_WIDTH-1 downto 0);
   signal memreg  : std_logic_vector(DATA_BUS_WIDTH-1 downto 0);
   signal burst_counter : std_logic_vector(3 downto 0);
@@ -248,7 +248,7 @@ begin
       flash_page(12 downto 0)  <= spi_flash_page(12 downto 0);
       flash_page(15 downto 13) <= "000";
       select_cfg <= '1';
-      if (spi_flash_page(12 downto 10) = "111" or enable_cfg_flash = '0') then
+      if (spi_flash_page(12 downto 10) = "111" or enable_cfg_flash(0) = '0') then
         select_cfg <= '0';
         flash_page(12 downto 10) <= "000";
       end if;
@@ -260,7 +260,7 @@ begin
       select_cfg <= '0';
     else
       flash_page <= spi_flash_page;
-      select_cfg <= enable_cfg_flash;
+      select_cfg <= enable_cfg_flash(0);
     end if;
   end if;
 end process;                          
@@ -322,7 +322,17 @@ PROC_SELECTOR : process begin
       readback_reg     <= SPI_DATA_IN(15 downto 8);
     elsif (SPI_ADDR_IN(7 downto 0) = x"5C") then
       reg_LOC_WRITE_OUT <= '0';
-      enable_cfg_flash <= SPI_DATA_IN(0);
+      if SPI_DATA_IN(0) = '0' then
+        enable_cfg_flash(2 downto 0) <= "000";
+      elsif SPI_DATA_IN(2 downto 0) = "011" and enable_cfg_flash(2 downto 0) = "000" then --stage1
+        enable_cfg_flash(2 downto 0) <= "010";
+      elsif SPI_DATA_IN(2 downto 0) = "101" and enable_cfg_flash(2 downto 0) = "010" then --stage2
+        enable_cfg_flash(2 downto 0) <= "100";
+      elsif SPI_DATA_IN(2 downto 0) = "001" and enable_cfg_flash(2 downto 0) = "100" then --stage3
+        enable_cfg_flash(2 downto 0) <= "001";
+      else
+        enable_cfg_flash(2 downto 0) <= "000";
+      end if;        
       --flash_mode       <= SPI_DATA_IN(8);  --XXX
     elsif (SPI_ADDR_IN(7 downto 0) = x"5d") then
       reg_LOC_WRITE_OUT <= '0';
@@ -336,7 +346,7 @@ PROC_SELECTOR : process begin
       reg_LOC_WRITE_OUT <= '0';
       if (flash_mode = '0' and USE_OLD_13BIT_MODE = c_YES) then
         spi_flash_command <= SPI_DATA_IN(15 downto 13);
-        if (enable_cfg_flash = '1') then
+        if (enable_cfg_flash(0) = '1') then
           spi_flash_page <= "000" & SPI_DATA_IN(12 downto 0);
         else
           spi_flash_page <= "000111" & SPI_DATA_IN(9 downto 0);
@@ -464,7 +474,7 @@ PROC_SELECTOR : process begin
       reg_LOC_READ_OUT  <= '0';
       reg_SPI_READY_OUT <= '1';
       reg_SPI_DATA_OUT(DATA_BUS_WIDTH-1 downto 0) <= (others => '0');
-      reg_SPI_DATA_OUT(15 downto 0) <= x"0" & "000" & flash_mode & '0' & auto_reset & "00" & '0' & flash_busy & flash_err & enable_cfg_flash;
+      reg_SPI_DATA_OUT(15 downto 0) <= x"0" & "000" & flash_mode & '0' & auto_reset & "00" & '0' & flash_busy & flash_err & enable_cfg_flash(0);
     elsif (SPI_ADDR_IN(7 downto 0) = x"5d") then
       reg_LOC_READ_OUT  <= '0';
       reg_SPI_READY_OUT <= '1';