Generated code canot be compiled with VHDL 93 only tools.

[ppisa]

Generated code canot be compiled with VHDL 93 only tools.

[ppisa]

When definition of memory_reg component is changed to use std_logic_vector without
defined index range for data_mask, reset_value and auto_clear generics then
literal constant is interpreted as array with ascending range which is counterintuitive
when masks should be generated in this order. Solution is to add function which
examines if input is array with ascending index range and in such case modify
masks indexing.

diff memory_reg.vhd generated/memory_reg.vhd
index 1da3851..3778de0 100644
--- generated/memory_reg.vhd
+++ generated/memory_reg.vhd
@@ -46,17 +46,17 @@ entity memory_reg is
 
         -- Data mask. Each logic 1 indicates present bit, logic 0 indicates
         -- reserved bit in register bits. Reserved bit always returns 0.
-        constant data_mask            :     std_logic_vector(data_width - 1 downto 0);
+        constant data_mask            :     std_logic_vector;
 
         -- Reset polarity
         constant reset_polarity       :     std_logic := '0';
 
         -- Reset value of register
-        constant reset_value          :     std_logic_vector(data_width - 1 downto 0);
+        constant reset_value          :     std_logic_vector;
 
         -- If given bit of the register should be cleared automatically one
         -- clock cycle after writing.
-        constant auto_clear           :     std_logic_vector(data_width - 1 downto 0)
+        constant auto_clear           :     std_logic_vector
     );
     port(
         ------------------------------------------------------------------------
@@ -84,6 +84,17 @@ end entity memory_reg;
 
 architecture rtl of memory_reg is
 
+    pure function bit_in_mask(mask_vec: std_logic_vector; bit_pos : natural)
+                                        return std_ulogic is
+    begin
+       if mask_vec'ascending then
+           return mask_vec(mask_vec'length - 1 - bit_pos);
+       else
+           return mask_vec(bit_pos);
+       end if;
+       --return mask_vec(bit_pos);
+    end function bit_in_mask;
+
     -- Register implementation itself!
     signal reg_value_r          :   std_logic_vector(data_width - 1 downto 0);
 
@@ -112,16 +123,16 @@ begin
     -- Register instance
     ----------------------------------------------------------------------------
     bit_gen : for i in 0 to data_width - 1 generate
-    
+
         ------------------------------------------------------------------------
         -- Register implementation itself
         ------------------------------------------------------------------------
-        reg_present_gen : if (data_mask(i) = '1') generate
+        reg_present_gen : if (bit_in_mask(data_mask, i) = '1') generate
 
             reg_access_proc : process(clk_sys, res_n)
             begin
                 if (res_n = reset_polarity) then
-                    reg_value_r(i)  <= reset_value(i);
+                    reg_value_r(i)  <= bit_in_mask(reset_value, i);
 
                 elsif (rising_edge(clk_sys)) then
 
@@ -131,8 +142,9 @@ begin
 
                     -- Clear the register if autoclear is set and register is
                     -- set
-                    elsif (auto_clear(i) = '1' and reg_value_r(i) = '1') then
-                        reg_value_r(i)  <= reset_value(i);
+                    elsif (bit_in_mask(auto_clear, i) = '1' and
+                           reg_value_r(i) = '1') then
+                        reg_value_r(i)  <= bit_in_mask(reset_value, i);
                     end if;
 
                 end if;
@@ -144,8 +156,8 @@ begin
         -----------------------------------------------------------------------
         -- Registers which are not present are stuck at reset value
         -----------------------------------------------------------------------
-        reg_not_present_gen : if (data_mask(i) = '0') generate
-            reg_value_r(i)    <=  reset_value(i);
+        reg_not_present_gen : if (bit_in_mask(data_mask, i) = '0') generate
+            reg_value_r(i)    <=  bit_in_mask(reset_value, i);
         end generate reg_not_present_gen;
 
     end generate bit_gen;

[Blebowski]

Hi, your patch was applied to "memory_reg.vhd" template. Now it should be supported by non-VHDL2008
tools.