Working with strings and characters in VHDL.

[amisin]

I have to access each element of a string via a character. So for that I will be using a for loop, but how do we access a specific element of a string. like for string str(1 to 8), if I wish to assign, str(4) to the character variable chr, how exactly we do that?

for loopcounter in 0 to 63 loop -- one end loop pending at end.
TestValueCharacter := O_LogisticCode(loopcounter + 1);
if(TestValueCharacter = '0') then
TestValueReal := 0;
elsif(TestValueCharacter = '1') then
TestValueReal := 1;
elsif(TestValueCharacter = '2') then
TestValueReal := 2;
elsif(TestValueCharacter = '3') then
TestValueReal := 3;
end if;

Here TestValueCharater is of character type, and TestValueReal is of real type. And O_LogisticCode is a string.

 

[TrickyDicky]

O_LogisticCode(loopcounter+1) := some_char.

I dont understand exactly what your problem is. You're doing the reverse with the current code.

Btw, to assign real values, you need to assign them like this:

TestValueReal := 1.0;
etc.

you need the .0, otherwise it thinks it is an integer.