Multi-Dimensional Array Signals and Variables Coding Examples - 2022.1 English

The following coding examples demonstrate the uses of multi-dimensional array signals and variables in assignments.

1.Make the following declarations:

subtype WORD8 is STD_LOGIC_VECTOR (7 downto 0);

type TAB05 is array (4 downto 0) of WORD8;

type TAB03 is array (2 downto 0) of TAB05;

signal WORD_A : WORD8;

signal TAB_A, TAB_B : TAB05;

signal TAB_C, TAB_D : TAB03;

constant CNST_A : TAB03 := (

("00000000","01000001","01000010","10000011","00001100"),

("00100000","00100001","00101010","10100011","00101100"),

("01000010","01000010","01000100","01000111","01000100"));

2.You can now specify:

°A multi-dimensional array signal or variable:

TAB_A <= TAB_B; TAB_C <= TAB_D; TAB_C <= CNST_A;

°An index of one array:

TAB_A (5) <= WORD_A; TAB_C (1) <= TAB_A;

°Indexes of the maximum number of dimensions:

TAB_A (5) (0) <= ’1’; TAB_C (2) (5) (0) <= ’0’

°A slice of the first array

TAB_A (4 downto 1) <= TAB_B (3 downto 0);

°An index of a higher level array and a slice of a lower level array:

TAB_C (2) (5) (3 downto 0) <= TAB_B (3) (4 downto 1); TAB_D (0) (4) (2 downto 0)

\\ <= CNST_A (5 downto 3)

3.Add the following declaration:

subtype MATRIX15 is array(4 downto 0, 2 downto 0) of STD_LOGIC_VECTOR (7 downto 0);

signal MATRIX_A : MATRIX15;

4.You can now specify:

°A multi-dimensional array signal or variable:

MATRIXA <= CNST_A

°An index of one row of the array:

MATRIXA (5) <= TAB_A;

°Indexes of the maximum number of dimensions

MATRIXA (5,0) (0) <= ’1’;

Note:   Indexes can be variable.