Compilation error

[YesMann]

Hello,
I have error in the process below;
My process is:

1. process(cycle)
2. begin
3. case cycle is
4.
5.
6. WHEN "000000" | "000001" | "000010" => REG <= "001000";
7. WHEN "000011" to "011101" => REG <= "000000";
8. WHEN "011110" | "011111" | "100000" => REG <= "001010";
9. WHEN "100001" => REG <=
"000010";
10. WHEN "100010" | "100011" | "100100" => REG <= "001101";
11. WHEN "100101" to "101000" => REG <= "000101";
12.
13. WHEN OTHERS => REG <="000000";
14.
15. end case;
16. end process;

The line 7 and 11 are considered as error : " Range must be a scalar type".
What can I specified the range "000011" to "011101" in VHDL language ?

Thanks in advance

 

[Jonathan Bromley]

[...]

3. case cycle is [...]
7. WHEN "000011" to "011101" => REG <= "000000"; [...]

The line 7 and 11 are considered as error : " Range must be a scalar type".
What can I specified the range "000011" to "011101" in VHDL language ?

You can't. However, you are using these values rather like numbers,
so it may be easier to convert them to integers for use in the case
statement:

case to_integer(cycle) is
...
when 3 to 29 => REG <= "000000";
...

Of course, the precise form of "to_integer" depends on what
numeric packages you are using, and the data type of "cycle".
If "cycle" is the output of a counter, and you have been
sensible and used ieee.numeric_std, and cycle is of type
UNSIGNED, then to_integer() is correct.

 

[YesMann]

case to_integer(cycle) is
...
when 3 to 29 => REG <= "000000";
...

Of course, the precise form of "to_integer" depends on what
numeric packages you are using, and the data type of "cycle".
If "cycle" is the output of a counter, and you have been
sensible and used ieee.numeric_std, and cycle is of type
UNSIGNED, then to_integer() is correct.

_______________________________

Thanks you for your response;
But if I process as your description, I have another message error:
"Type error in range expression";
What happened?

Thanks in advance