Description
Partitions an array into smaller arrays or individual elements.
This partitioning:
- Results in RTL with multiple small memories or multiple registers instead of one large memory.
- Effectively increases the amount of read and write ports for the storage.
- Potentially improves the throughput of the design.
- Requires more memory instances or registers.
Syntax
set_directive_array_partition [OPTIONS] <location> <array>
-
<location>
is the location (in the formatfunction[/label]
) which contains the array variable. -
<array>
is the array variable to be partitioned.
Options
-
-dim <integer>
-
Note: Relevant for multi-dimensional arrays only.Specifies which dimension of the array is to be partitioned.
- If a value of 0 is used, all dimensions are partitioned with the specified options.
- Any other value partitions only that dimension. For example, if a value 1 is used, only the first dimension is partitioned.
-
-factor <integer>
-
Note: Relevant for typeSpecifies the number of smaller arrays that are to be created.
block
orcyclic
partitioning only. -
-type (block|cyclic|complete)
-
-
block
partitioning creates smaller arrays from consecutive blocks of the original array. This effectively splits the array into N equal blocks where N is the integer defined by the-factor
option. -
cyclic
partitioning creates smaller arrays by interleaving elements from the original array. For example, if-factor 3
is used:- Element 0 is assigned to the first new array.
- Element 1 is assigned to the second new array.
- Element 2 is assigned to the third new array.
- Element 3 is assigned to the first new array again.
-
complete
partitioning decomposes the array into individual elements. For a one-dimensional array, this corresponds to resolving a memory into individual registers. For multi-dimensional arrays, specify the partitioning of each dimension, or use-dim 0
to partition all dimensions.
complete
. -
Examples
Partitions array AB[13] in function foo
into four arrays. Because four is not an integer factor of 13:
- Three arrays have three elements.
- One array has four elements (AB[9:12]).
set_directive_array_partition -type block -factor 4 foo AB
Partitions array AB[6][4] in function foo
into two arrays, each of dimension [6][2].
set_directive_array_partition -type block -factor 2 -dim 2 foo AB
Partitions all dimensions of AB[4][10][6] in function foo
into individual elements.
set_directive_array_partition -type complete -dim 0 foo AB