record of a record to std_logic_vector

[THurkmans]

Hello,

I've made a design in which I have a few blocks which I want to
synthesize. My simulation is working, and now I'm trying to do a post-
synthesis simulation per block by replacing each block with its
synthesized version.

What I didn't expect from my synthesis tool was that it would mess up
my entities in which I use records. I have created a small records to
pass my memories to my block:

type ram_image_type is record
enable : std_logic;
write_enable : std_logic;
address : std_logic_vector(17 downto 0);
inoutput : std_logic_vector(7 downto 0);
end record;

type memories_inout_type is record
image0 : ram_image_type;
image1 : ram_image_type;
image2 : ram_image_type;
end record;

I've found posts which create to_vec and from_vec, and align the
vectors such that they can be used in one std_logic_vector, but those
only assume one record. How can I create a to_std_logic_vector for the
memories_inout_type record?

 

[Andy]

Hello,

I've made a design in which I have a few blocks which I want to
synthesize. My simulation is working, and now I'm trying to do a post-
synthesis simulation per block by replacing each block with its
synthesized version.

What I didn't expect from my synthesis tool was that it would mess up
my entities in which I use records. I have created a small records to
pass my memories to my block:

type ram_image_type is record
        enable : std_logic;
        write_enable : std_logic;
        address : std_logic_vector(17 downto 0);
        inoutput : std_logic_vector(7 downto 0);
end record;

type memories_inout_type is record
        image0 : ram_image_type;
        image1 : ram_image_type;
        image2 : ram_image_type;
end record;

I've found posts which create to_vec and from_vec, and align the
vectors such that they can be used in one std_logic_vector, but those
only assume one record. How can I create a to_std_logic_vector for the
memories_inout_type record?

Maybe create a function which calls the little "record_to_slv"
function for each sub-record, concatenating the results?

BTW, anytime you have a record which contains three (or 'N') identical
items, it should probably be an array, not a record. Arrays allow you
to index the elements using loops, variables/signals, etc.

Andy

 

[KJ]

I've found posts which create to_vec and from_vec, and align the
vectors such that they can be used in one std_logic_vector, but those
only assume one record. How can I create a to_std_logic_vector for the
memories_inout_type record?

By first creating to_vec and from_vec functions that work with
'ram_image_type'. Then the to_vec and from_vec for
'memories_inout_type' would call the to_vec and from_vec for each of
the elements of the record. One possible way is...

function to_vec(R: memories_inout_type) is
begin
return(to_vec(R.image0) & to_vec(R.image1) & to_vec(R.image2));
end function to_vec;

To do the 'from_vec' function you'd have to know the size of the
vector that is returned from the 'from_vec' function that works with
'ram_image_type' so that you can strip out the appropriate set of bits
so that you can then call from_vec with it.

Kevin Jennings