FPGA Central

Dear

I would like to have some suggestion to implement 'regular 40
instances'.

I use following "2D array" signal :

Array (0 to 4) of array (0 to 4) of integer (0 to 4)

Now I have choices that:

--------------------------------------------------------
1. Make different "2D array typed" signals.
Manually modify each instance for different signals.

2. Make generic "3D array typed" signal :

Array (0 to 39) of array (0 to 4) of array (0 to 4) of integer (0
to 4)

Then make all generic.
--------------------------------------------------------

"Choice 1" is too laborious and error-prone.
I am not sure there is a good synthesizer tool for the "Choice 2"

I am currently using Xilinx XST tool (version 8.2).

If someone has experience of synthesizing 3D-array signal, please let
us know.

On Nov 13, 1:35 am, Pasacco <[email protected]> wrote:
> Dear
>
> I would like to have some suggestion to implement 'regular 40
> instances'.
>
> I use following "2D array" signal :
>
> Array (0 to 4) of array (0 to 4) of integer (0 to 4)
>
> Now I have choices that:
>
> --------------------------------------------------------
> 1. Make different "2D array typed" signals.
> Manually modify each instance for different signals.
>
> 2. Make generic "3D array typed" signal :
>
> Array (0 to 39) of array (0 to 4) of array (0 to 4) of integer (0
> to 4)
>
> Then make all generic.
> --------------------------------------------------------
>
> "Choice 1" is too laborious and error-prone.
> I am not sure there is a good synthesizer tool for the "Choice 2"
>
> I am currently using Xilinx XST tool (version 8.2).
>
> If someone has experience of synthesizing 3D-array signal, please let
> us know.

Hallo

I can tell you about my multi dimensional array experience:

-- Definitions about Colors and RGB-Data
type COLORS_T is (RED, GREEN, BLUE);
type RGB_DATA_T is array (COLORS_T) of std_logic_vector(7 downto 0);

constant DelayInPixels : integer := 2;
type PixIn_Dly_T is array(DelayInPixels-1 downto 0) of RGB_DATA_T;
signal PixIn_Dly : PixIn_Dly_T;

PixIn_Dly <= PixIn_Dly(PixIn_Dly'left-1 downto PixIn_Dly'right) &
PixIn;


The delay line for PixIn_Dly wasn't synthesized correct.
I think the PinIn_Dly as an array() of [array(COLORS_T) of
std_logic_vector(7 downto 0)] was too much for XST. I used ISE 8.1.03

Have fun
Florian

> The delay line for PixIn_Dly wasn't synthesized correct.
> I think the PinIn_Dly as an array() of [array(COLORS_T) of
> std_logic_vector(7 downto 0)] was too much for XST. I used ISE 8.1.03

Thank you for comment.
In the XST document, XST does support 3D-array type signal synthesis.
How did you resolve the problem then? Did you synthesize using 2D-
type ?

On Nov 12, 7:35 pm, Pasacco <[email protected]> wrote:
> Dear
>
> I would like to have some suggestion to implement 'regular 40
> instances'.
>
> I use following "2D array" signal :
>
> Array (0 to 4) of array (0 to 4) of integer (0 to 4)
>
> Now I have choices that:
>
> --------------------------------------------------------
> 1. Make different "2D array typed" signals.
> Manually modify each instance for different signals.
>
> 2. Make generic "3D array typed" signal :
>
> Array (0 to 39) of array (0 to 4) of array (0 to 4) of integer (0
> to 4)
>
> Then make all generic.
> --------------------------------------------------------
>
> "Choice 1" is too laborious and error-prone.
> I am not sure there is a good synthesizer tool for the "Choice 2"
>
> I am currently using Xilinx XST tool (version 8.2).
>
> If someone has experience of synthesizing 3D-array signal, please let
> us know.

what about a type definition such as:

type matrix is array (natural range<>, natural range<>) of real;

can we expand this to have a third index :

type matrix3d is array (natural range<>, natural range<>, natural
range<>) of real;

Thank you for comments.

I am simulating the VHDl. But it seems that XST well synthesizes 3D-
type signal (at least following types).

---------------------------
type OneD is array(0 to 4) of integer range 0 to 4;
type TwoD is array(0 to 4) of OneD;
type ThreeD is array(0 to 4) of TwoD;
---------------------------