In the code below, the main controller sends the “acc” signal to the accumulator, which accumulates “in” on the variable "psum". Once the “acc” signal goes low, the accumulated value is supposed to be reset to zero. Fill in the blanks with the correct variables from the options (you can put the same variable in multiple blanks): [acc_done/psum/in/acc/acc_cnt/num_limit]   if (acc) begin     if (acc_cnt == num_limit)  begin         acc_done <= 1;         …    end     else begin         [Fill in the blank], <= [Fill in the blank], + 1;         psum <= in + psum;     end end else begin     acc_done <= 0;     [Fill in the blank], <= 0; end     多项填空题