Honored ContributorMy code:
Int is an Integer Variable OutputNumber is a Std_logic_Vector Input Int <= conv_integer(OutputNumber); MyVector(37 downto (38-Int)) <= Temp(37 downto (38-Int)); Quartus Compiler Error: Error (10454): VHDL syntax error: right bound of range must be a constant PLEASE HELP ME.
Honored ContributorThe VHDL standard does not allow the right-hand side of downto expresions to contain a variable.
Just use a constant instead of a Int Integer variable.Honored ContributorThanks for reply, but i don't know the value of Int. I must convert the "OutputNumber" input to know the value of Int.
Honored ContributorFrom your code snippet, it's not fully clear, what you want to achieve. If you want to copy a variable number of bits depending on another condition, you can use a for loop iteration scheme.
for i in 0 to 37 loop
if i >= 38 - int then
MyVector(i) <= Temp(i);
end if;
end loop;Hello,
"OutputNumber" is a Std_logic_Vector(5 downto 0). It is a vector that store the number of output (eg.: "000000" means no outputs; "01010" means 10 outputs and so on....) The integer variable "Int" store the equivalent integer value: No outputs: Int:=0; 10 outputs: Int:=10 and so on..... "Temp" is a 38bit vector, but i need to copy only a range to "MyVector" Int <= conv_integer(OutputNumber); MyVector(37 downto (38-Int)) <= Temp(37 downto (38-Int)); Quartus Compiler Error: Error (10454): VHDL syntax error: right bound of range must be a constantHonored ContributorAmilcar has already explained, that your code isn't valid VHDL. Try as I suggested or use a similar construct according to VHDL syntax rules.
Honored ContributorOk, so can you help me with an alternative solution?
Honored ContributorFvM already gave you an alternative solution.
One other solution would be: if (OutputNumber == "000000") then MyVector(37 downto (38-0)) <= Temp(37 downto (38-0)); <- This is wrong because your code was wrong end if (OutputNumber == "000001") then MyVector(37 downto (38-1)) <= Temp(37 downto (38-1)); end if (OutputNumber == "000010") then MyVector(37 downto (38-2)) <= Temp(37 downto (38-2)); end if (OutputNumber == "000011") then MyVector(37 downto (38-3)) <= Temp(37 downto (38-3)); end if (OutputNumber == "000100") then MyVector(37 downto (38-4)) <= Temp(37 downto (38-4)); end ... if (OutputNumber == "01010") then MyVector(37 downto (38-10)) <= Temp(37 downto (38-10)); end There is no need to use conv_integer. And pleas use numeric_std instead of standard_arith
