During Multiply-Add and Multiply-Accumulate implementation:
• Vivado synthesis can implement an inferred Multiply-Add or Multiply-Accumulate macro on DSP block resources.
• Vivado synthesis attempts to take advantage of the pipelining capabilities of DSP blocks.
• Vivado synthesis pulls up to:
° Two register stages present on the multiplication operands.
° One register stage present after the multiplication.
° One register stage found after the Adder, Subtractor, or Adder/Subtractor.
° One register stage on the add/sub selection signal.
° One register stage on the Adder optional carry input.
• Vivado synthesis can implement a Multiply Accumulate in a DSP block if its implementation requires only a single DSP resource.
• If the macro exceeds the limits of a single DSP then Vivado synthesis does the following:
° Processes it as two separate Multiplier and Accumulate macros.
° Makes independent decisions on each macro.