System Verilog

# System Verilog : Array querying system functions

System Verilog provides some system functions to query about arrays. The return value of this system function is `int` and it can be applied to all arrays.

Different array querying functions are

\$dimension :
Returns the number of dimensions in the array and 1 for strings and simple bit vectors and 0 for any other type.

Here there are two dimensions for mem i.e. one `packed` and one `unpacked` ( [15:0] and 1:63]).For myarr there are two `packed` and two `unpacked` dimensions. So total 4.

\$unpacked_dimensions :
Returns the number of unpacked dimensions of an array and 0 for any other type.

Here, one unpacked dimension for mem (i.e. 1:63) and 2 unpacked dimensions for myarr (2:0,3:0).

\$left :
Returns the left declared bound of the dimension.

Here first unpacked dimension will be used. For mem, 1:63 is the unpacked dimension and left bound is 1.
For myarr, 2:0 is the unpacked dimension and 2 will be the \$left value.

\$right :
Returns the right declared bound of the dimension.

Just like \$left, \$right will be the right bound. So for mem, 1:63 is the dimesion and \$left value is 1 and \$right value is 63.For myarr \$left is 2 and \$right is 0.

\$low :
Returns the lowest declared bound of the dimension.

Lowest declared bound of the dimension for mem is 1 and for myarr is 0.

\$high :
returns the highest declared bound of the dimension.

Highest declared bound of the dimension for mem is 63 and for myarr is 2.

\$increment :
Returns 1 if the left bound is greater than or equal to the right bound and -1 otherwise.

For mem, left bound is less than right bound, so returned -1.
For myarr, left bound is greater than right bound, so returned 1.

\$size :
Returns the number of elements in the dimension.

Here, number of elements in mem is 63 (1:63 dimension) and myarr has 3 elements.

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