parametric vector slices

[alb]

Hi everyone,

I'm not sure if the 'subject' is correctly formulated but I'll try anyway.

Assume an array of bits 'a' which has N number of bits. Now assume M < N
where N/M = k is an integer number. I'd like to slice a in k pieces in
such a way that I can assign each slice to another array of bits with M
bits.

Something like this:

<code>

--not tested
variable a : my_array_of_bits(N-1 downto 0);

type list is array (0 to k) of my_array_of_bits(M-1 downto 0);
variable l : list;

for i in 0 to l'range - 1 loop
l(i) <= a((i+1)*M - 1 downto i*M);
end loop;

</code>

Is there any better way to do this?

Al

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[Andy]

Al,

For vhdl-2008 compliant tools, you can declare a type that is an unconstrained array of unconstrained arrays, so it is possible to write a "slice(input, M)" function that would return such a type. You may want a function that does the reverse too.

Check your tools' documentation to see which 2008 features they support.

Andy