Large array in VHDL , too much resouces required any other options?

Large array in VHDL , too much resources required

Hi,
In 1 clock cycle, my design output
output_real : out std_logic_VECTOR(15 downto 0);
I have to run my design for 2048x64 clk and store all the 2048x64 output_real to be used later.

Problem is I tried to store the whole output in a "Signal" format ( array of size [2048][64][16] )but it is too large, are there any alternative solutions?
I'm thinking of writing it into a table but not sure how to do it.

Below is how I declare my output array:
type N2048_16 is array( 0 to 2047) of std_logic_vector( 15 downto 0 );
type 64Channel_N2048_16 is array( 0 to 63) of N2048_16;



Thanks in advance for advice!

thats 256k of ram, IF (and a big if) you accessed the array correctly so that the synthesisor infered a RAM, and if you have a large enough part. If rams are not inferred, I bet it took a long time to compile (if rams were infered, it shouldnt take too long).

So, more detail needed:
Wheres the code the accesses the "RAM"?
What part are you using?

NOTE: This is not technically a 2D array - its 3x 1D arrays.

- - - Updated - - -

PS> 256Kb (2Mbits of ram) is rather large for a single application. you will need a medium to large part to have enough ram.

Re: Large array in VHDL , too much resources required

TON2 said:

Hi,
In 1 clock cycle, my design output
output_real : out std_logic_VECTOR(15 downto 0);
I have to run my design for 2048x64 clk and store all the 2048x64 output_real to be used later.

Problem is I tried to store the whole output in a "Signal" format ( array of size [2048][64][16] )but it is too large, are there any alternative solutions?
I'm thinking of writing it into a table but not sure how to do it.

Below is how I declare my output array:
type N2048_16 is array( 0 to 2047) of std_logic_vector( 15 downto 0 );
type 64Channel_N2048_16 is array( 0 to 63) of N2048_16;



Thanks in advance for advice!

Click to expand...

1. use a very big fpga.
2. use external memory.

Thanks for your replies, I am using Xilinx Vertex6 XC6VSX475T.

So guess I have to study about using external RAM right?
If any one have good references or manual please advise.

Thanks again

TON2 said:

Thanks for your replies, I am using Xilinx Vertex6 XC6VSX475T.

So guess I have to study about using external RAM right?
If any one have good references or manual please advise.

Thanks again

Click to expand...

Possibly - but you didnt post the code thats causing the device to run out of RAM. That part has 7 Mbits of ram, and you only need 256k. I suspect you're not using the array properly to infer the RAM.