🐛 [rtl] fix is_power_of_two VHDL function

CHANGELOG.md

@@ -32,6 +32,7 @@ mimpid = 0x01040312 => Version 01.04.03.12 => v1.4.3.12
 
 | Date (*dd.mm.yyyy*) | Version | Comment |
 |:-------------------:|:-------:|:--------|
+| 15.10.2022 | 1.7.7.3 | :bug: fix bug in `is_power_of_two_f` VHDL function (thanks Alan!); [#482](https://github.com/stnolting/neorv32/pull/428) |
 | 12.10.2022 | 1.7.7.2 | add dedicated hardware reset to _all_ CPU counters (`[m]cycle[h]`, `[m]instret[h]`, `[m]hpmcounter[h]`); :sparkles: **all CSRs now provide a dedicated hardware reset**; [#426](https://github.com/stnolting/neorv32/pull/426) |
 | 09.10.2022 | 1.7.7.1 | fix Quartus synthesis issue (VHDL): make sure reset state is the _first_ entry in a state list [#423](https://github.com/stnolting/neorv32/pull/423) |
 | 24.08.2022 | [**:rocket:1.7.7**](https://github.com/stnolting/neorv32/releases/tag/v1.7.7) | **New release** |

rtl/core/neorv32_package.vhd

@@ -58,7 +58,7 @@ package neorv32_package is
 
   -- Architecture Constants (do not modify!) ------------------------------------------------
   -- -------------------------------------------------------------------------------------------
-  constant hw_version_c : std_ulogic_vector(31 downto 0) := x"01070702"; -- NEORV32 version - no touchy!
+  constant hw_version_c : std_ulogic_vector(31 downto 0) := x"01070703"; -- NEORV32 version - no touchy!
   constant archid_c     : natural := 19; -- official RISC-V architecture ID - hands off!
 
   -- Check if we're inside the Matrix -------------------------------------------------------
@@ -2475,13 +2475,19 @@ package body neorv32_package is
   -- Function: Test if input number is a power of two ---------------------------------------
   -- -------------------------------------------------------------------------------------------
   function is_power_of_two_f(input : natural) return boolean is
+    variable tmp : unsigned(31 downto 0);
   begin
-    if (input = 1) then -- 2^0
-      return true;
-    elsif ((input / 2) /= 0) and ((input mod 2) = 0) then
+    if (input = 0) then
+      return false;
+    elsif (input = 1) then
       return true;
     else
-      return false;
+      tmp := to_unsigned(input, 32);
+      if ((tmp and (tmp - 1)) = 0) then
+        return true;
+      else
+        return false;
+      end if;
     end if;
   end function is_power_of_two_f;