mac_reduced_param.v

module mac #(parameter S_WIDTH=4, W_WIDTH=4, MULT_WIDTH = 8, ACC_PR_WIDTH = 10, ACC_WIDTH = 6)    (in1, in2, clk, reset, acc);
   input signed [S_WIDTH-1:0] in1;
   input signed [W_WIDTH-1:0] in2;
   input       clk;
   output reg signed [ACC_WIDTH-1:0] acc;
   input        reset;

   reg signed [MULT_WIDTH-1:0]   out_mult;
   reg signed [ACC_PR_WIDTH:0]   acc_pre_reduced;

   always @(posedge clk or posedge reset)
     begin
        out_mult <= in1*in2;
        if (reset)
          begin
             acc_pre_reduced <= 0;
             acc <= 0;
          end
        else
          acc_pre_reduced = out_mult+acc_pre_reduced;
          if (acc_pre_reduced > 2**(ACC_WIDTH-1))          acc = 2**(ACC_WIDTH-1)-1;
          else if (acc_pre_reduced < -(2**(ACC_WIDTH-1)))          acc = -2**(ACC_WIDTH-1);
          else acc = acc_pre_reduced;
     end

endmodule