When I use aoc to compile OpenCL kernel ，DSP utilization is limited to 25% .
At first , I used "#pragma unroll" to unroll the loop. when the number of unroll become bigger , The DSP blocks utilization increased.
But,when the number of unroll is bigger enough ,the DSP blocks utilization is limited to 25% .
Why does this happen？
board：Intel® Programmable Acceleration Card with Intel® Arria® 10 FPGA GX
SDK：Intel FPGA SDK for OpenCL 17.1
aoc compile report：
+--------------------------------------------------------------------+
; Estimated Resource Usage Summary ;
+----------------------------------------+---------------------------+
; Resource + Usage ;
+----------------------------------------+---------------------------+
; Logic utilization ; 78% ;
; ALUTs ; 48% ;
; Dedicated logic registers ; 34% ;
; Memory blocks ; 57% ;
; DSP blocks ; 25% ;
+----------------------------------------+---------------------------;
aoc compile report(when number of unroll become bigger)：
+--------------------------------------------------------------------+
; Estimated Resource Usage Summary ;
+----------------------------------------+---------------------------+
; Resource + Usage ;
+----------------------------------------+---------------------------+
; Logic utilization ; 176% ;
; ALUTs ; 130% ;
; Dedicated logic registers ; 60% ;
; Memory blocks ; 74% ;
; DSP blocks ; 25% ;
+----------------------------------------+---------------------------;