VHDL GENERIC Multidimensional Array

Question

I use this ENTITY :

ENTITY SPI_PT100 IS
GENERIC
(
    PT100_DATA_SIZE     : INTEGER := 8; --nombre de data à envoyer par trame
    PT100_NB_MOSI       : INTEGER := 3; --nombre de ligne MOSI
    PT100_10ms_CNT      : INTEGER := 400000; --nb tick in_clk entre deux trames (défaut 10ms @ 40Mhz) 
    PT100_500ns_CNT     : INTEGER := 20 --nb de tick in_clk entre deux changement d'état sur SCLK (1/2 periode) (défaut : sclk = 1Mhz)
);
PORT
(
    --input
    in_clk          : IN  STD_LOGIC; --40Mhz
    in_data         : IN STD_LOGIC_VECTOR((PT100_DATA_SIZE-1) DOWNTO 0); --data à envoyer
    --output
    out_spi_sclk    : OUT  STD_LOGIC := '0'; --clk du SPI 
    out_spi_u_sync  : OUT STD_LOGIC := '1'; -- u_sync du SPI
    out_spi_mosi    : OUT  STD_LOGIC := '0' -- mosi du SPI
);
END ENTITY;

I want to use PT100_NB_MOSI as a generic multiaray size :

in_data : IN STD_LOGIC_VECTOR((PT100_DATA_SIZE-1) DOWNTO 0); ==> 
in_data : IN STD_LOGIC_VECTOR((PT100_NB_MOSI-1) DOWNTO 0)) OF ((PT100_DATA_SIZE-1) DOWNTO 0);

I know that I can do it using a type or a subtype but in this case I think I must use a package. Is there a solution using only GENERIC mechanism ?

Answer 1

Unfortunately not. What you can do is use a one-dimensional vector:

in_data : IN STD_LOGIC_VECTOR((PT100_NB_MOSI*PT100_DATA_SIZE-1) DOWNTO 0);

And access in_data(i*PT100_DATA_SIZE+j) for accessing the (i, j) array element.

Else, you have to declare it in a package file as an array:

type my_arr is array(natural range <>) of std_logic_vector(PT100_DATA_SIZE-1 DOWNTO 0);

Then include the array: use work.my_pkg.my_arr; (or use work.my_pkg.all; for the whole package) and use it in the interface: in_data : IN my_arr((PT100_NB_MOSI-1) DOWNTO 0);