Slice
Formal Definition
A one-dimensional array of a
sequence of consecutive elements of another one-dimensional array.
Simplified Syntax
object_name ( discrete_range )
function_call ( discrete_range )
Description
The slice is a subarray of
a one-dimensional array, from a single element up to complete array.
The prefix used for a slice is the name of the parent array.
The index used for a slice must fall in the range of the indexes of
the parent array. Moreover, the direction of the slice indexes must
be the same as the direction of indexes of parent array (either
ascending or descending).
The slice is an object which can be used in the same way as its
parent array: if the parent array is a signal, then any its slice is
also a signal, etc.
If the discrete range of a slice is null then the slice is null as well.
Examples
Example 1
signal DataBus : Bit_Vector(31
downto 0); -- parent array
DataBus(31 downto 26) --
slice 1
DataBus(24 downto 24) --
slice 2
DataBus(24 downto 30) --
slice 3
DataBus(15 to 31) -- no
slice - ERROR!
The first slice is a 6-element Subarray of the DataBus. The second
slice contains one element. Slice 3 is a null slice (the range is
null). Finally, the fourth example is an error due to different
directions of the parent array and the slice.
Important Notes
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