module V_jk_ff(q, qbar, clk, j, k);
 input clk,j,k;
 output q,qbar;
 voltage q, qbar, clk,j,k;
 parameter real tdelay   = 5n from [0:inf),
                ttransit = 5n from [0:inf),
                vout_high = 5,
                vout_low  = 0 from (-inf:vout_high),
                vth       = 1.4;

 integer x;

 analog
 begin
   @(initial_step) x = 0;

   @(cross(V(clk) - vth, +1))
   begin
     if (V(j) > vth)
       case (V(k) > vth)
         1 : x = !x;
         0 : x = 1;
       endcase
     else
       if (V(k) > vth) x = 0;
   end

   V(q)    <+ transition( vout_high*x  + vout_low*!x, tdelay, ttransit );
   V(qbar) <+ transition( vout_high*!x + vout_low*x , tdelay, ttransit );
 end
endmodule