Why are black boxes synthesized? ( in Verilog and FPGA design)

Verilog Q1: In a Xilinx FPGA, what is a control set? What does it contain? Q2: Xilinx says designs with asynchronous resets may use excess LUTs and registers. Briefly explain why.
Verilog Q1: In a Xilinx FPGA, what is a control set? What does it contain? Q2: Xilinx says designs with asynchronous resets may use excess LUTs and registers. Briefly explain why.
Verilog: Q1: 3rd party IP provides three files: a netlist; a behavioral wrapper; and a file showing the instantiation syntax. What is the purpose of the behavioral wrapper? Q2: Why are black boxes synthesized? Q3: Xilinx recommends control signals in modules be coded so they are active high. Why?
Regarding Verilog HDL (Xilinx FPGA in this case) ... 3rd party IP provides three files: a netlist; a behavioral wrapper; and a file showing the instantiation syntax. What is the purpose of the "behavioral wrapper"?
Why recommends control signals in modules be coded so they are active high? ( in Xilinx) ( Verilog and FPGA design)
Xilinx recommends control signals in modules be coded so they are active high. Why? (note: in Verilog and FPGA design)
Block diagram (modules and their relationship) of the ALU. Verilog code (your behavioral level design) for the mALU module. Verilog code (your data flow design) for the neg2pos module. Verilog code (using behavioral level design)of the bcd7seg Verilog module. Verilog code (using mixed data flow and behavioral level design) of the ALU_Top module. Testbench for the ALU_Top() module, and the simulation waveform by the testbench.
a) Write a verilog module for 1:4 Demultiplexer using verilog primitives. b) Design 1-to-4 DEMUX using tristate buffers in verilog. c) Write a code in NIOS-II assembly to execute following statement: b=(a+b)-(c+d)
2. Within Altera Quartus FPGA development software, once you created either RTI or Schematic design, ) how can you create Symbol file and how can you place it onto design window ?
Design an 8-bit full adder using Verilog (Use only 1-bit full adders). Write the design code, test-bench code of it, and test your design with six inputs. Note: Only use Verilog to design 8-bit full adder.