Hardware Buffer Depth
The syntax of this pragma is:
#pragma SDS data buffer_depth(ArrayName:BufferDepth)
Important:The hardware interpretation of this pragma might be revised in a future release.
This pragma must be specified immediately preceding a function declaration, or immediately preceding another#pragma SDS
bound to the function declaration, and applies to all the callers of the function.
Some notes about the syntax:
- Multiple arrays can be specified in one pragma, separated by a comma(,). For example:
#pragma SDS data buffer_depth(ArrayName1:BufferDepth1, ArrayName2:BufferDepth2)
ArrayName
must be one of the formal parameters of the function.BufferDepth
must a compile-time constant value.- This pragma applies only to arrays that map to BRAM or FIFO interfaces. For a BRAM-mapped array, the value specifies hardware multi-buffer depth. For a FIFO-mapped array, the value specifies the depth of the hardware FIFO allocated for the array. For this pragma, the following must hold:
- BRAM: 1 ≤ BufferDepth ≤ 4, and 2 ≤ ArraySize ≤ 16384.
- FIFO: BufferDepth = 2n, where 4 ≤ n ≤ 20.