FPGA Central

Hi,
I'd like to set up block rams(16k) to acts as a ROM lookup table
after initialization. After establishing the Memory Area as an FPGA
resource there's an option to initialize it by using memory eritor.
However, this would be very time consuming, as my memory is 16Kwords
deep. Is there some way to just reference an external text file, or
excel sheet at least automatically read/paste an external file for
this purpose?

and also How to combine both block memory and distributed memory
(using lut) to use as one memrory of 16k?
that is ,
I want 2 implenet 2 memory of size 16kX8 in fpga spartan-3 one a6X8
take 8 block ram out of 12 block ram available in fpga?
then when I tried to use only LUT as ram of size 16kX8 the resourses
are not enough.so can u tell me hoe to combine remainning 4 blokc ram
and LUTs to implement one more memory of size 16kX8

please mail to me at [email protected]

selva kumar <[email protected]> wrote:

>Hi,
> I'd like to set up block rams(16k) to acts as a ROM lookup table
>after initialization. After establishing the Memory Area as an FPGA
>resource there's an option to initialize it by using memory eritor.
>However, this would be very time consuming, as my memory is 16Kwords
>deep. Is there some way to just reference an external text file, or
>excel sheet at least automatically read/paste an external file for
>this purpose?

You can initialize the memory from the UCF file. You can write a
program which outputs the initialisers in UCF format and paste these
into the UCF file.

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selva kumar wrote:
> Hi,
> I'd like to set up block rams(16k) to acts as a ROM lookup table
> after initialization. After establishing the Memory Area as an FPGA
> resource there's an option to initialize it by using memory eritor.
> However, this would be very time consuming, as my memory is 16Kwords
> deep. Is there some way to just reference an external text file, or
> excel sheet at least automatically read/paste an external file for
> this purpose?
>
> and also How to combine both block memory and distributed memory
> (using lut) to use as one memrory of 16k?
> that is ,
> I want 2 implenet 2 memory of size 16kX8 in fpga spartan-3 one a6X8
> take 8 block ram out of 12 block ram available in fpga?
> then when I tried to use only LUT as ram of size 16kX8 the resourses
> are not enough.so can u tell me hoe to combine remainning 4 blokc ram
> and LUTs to implement one more memory of size 16kX8
>
> please mail to me at [email protected]
>

As far as initializing a memory the .coe file is the most convenient in
most applications. You can provide that file when you generate the
memory in coregen.

To combine a distributed memory with a bram memory you could generate
both parts as separate cores in coregen and combine them with your own
logic.