Simple test circuit for shx program.
* A typical command sequence in shx:
*  t1.cir
*  /lvals
*  /aevt
*  /elim 20
*  /dlim 20
*  /slim 20
*  /xnode clk div
*  run

* d_osc controlled by EXTERNAL source

vext ctl 0 0 external
aosc ctl clk osc
.model osc d_osc cntl_array = [0 20] freq_array = [ 100k 1meg ]

# Divide  by three so there will be multiple transitions, reported by /aevt
# within each time-step.

adiv clk div div
.model div d_fdiv div_factor = 3

* Add a resistor to convert to analogue and force breakpoints.

r div 0 100

* Use .tran so that /xnode commands can be given after loading.
* Set maximum time step above div cycle time, so breakpoints control
* time steps.  Long run time to overcome the 50 steps minimum.

.tran 4u 201u

.end