using multiple ranges

[paulk]

Hi..

I am trying to find an elegant method of concatenating multiple ranges.

Basically I have a signal

signal a is std_logic_vector(35 downto 00)
signal b is std_logic_vector(31 downto 00);

and I am doing the following remap:

b <= a(34 downto 27) & a(25 downto 18) & a(16 downto 9) & a(7 downto 0);

but for readability I would like to replace this statement with something like

b <= a(BYTE_MAP);

Does anyone know how to do this? It seems as though I need to define a subtype with multiple ranges.. is this possible?

ie.

SUBTYPE BYTE_MAP is range (34 downto 27) & range (25 downto 18) & range....


Thanks,

Paul