Re: 求教一道面试题

module test (/*AUTOARG*/
   // Outputs
   q_o,
   // Inputs
   clka_i, clkb_i, reset_n_i
   ) ;
   input clka_i;
   input clkb_i;
   input reset_n_i;
  
   output q_o;
   reg    outbuff_pos;
   reg    outbuff_neg;
   assign q_o = outbuff_pos ^ outbuff_neg;
   always @ ( negedge reset_n_i or posedge clka_i) begin
      if (!reset_n_i) begin
         /*autoreset*/
         // Beginning of autoreset for uninitialized flops
         outbuff_pos <= 1'h0;
         // End of automatics
      end
      else if (1)  begin
         if (outbuff_neg == 0) begin
            outbuff_pos <= 1;
         end
         else begin
            outbuff_pos <= 0;            
         end
      end      
   end
   always @ ( negedge reset_n_i or negedge clkb_i) begin
      if (!reset_n_i) begin
         /*autoreset*/
         // Beginning of autoreset for uninitialized flops
         outbuff_neg <= 1'h0;
         // End of automatics
      end
      else if (1)  begin
         if (outbuff_pos == 0) begin
            outbuff_neg <= 0;  
         end
         else begin
            outbuff_neg <= 1;            
         end
      end      
   end
  
endmodule // test