Several functions and variables are to be found in the c file generated by
a cyco run: 

void write_aet_header(void) : writes an aet header to stdio.

void write_aet_frame(int cycle, char *ptr) : writes an aet frame to stdio.  

char *facs[] : list of signals in your model

void sim_comb(void) : simulates combinational logic in the circuit

void sim_latch(void) : simulates the clocked latches in the circuit

void sim(void) : simulates combinational then latches
void sim_2(void) : simulates latches then combinational

...normally, you'd use sim().  if you need instantaneous turnaround on
combinational signals, you'll have to call sim_comb().  if you have logic
before your latches and combinational logic after latches which feeds
outputs, you'll have to call sim_comb() then sim_2() to get a "proper"
simulation.  it'll run normally, but w/o the combinational logic update
after the latch update, your combinational logic from outputs of latches
to circuit outputs will be one cycle late which may be incorrect depending
on your simulation strategy.  i've left this open-ended so you can do what
you need to simulate a model correctly but left the option that users can
select what gets run in what order to speed up simulation by not having
to evaluate combinational logic twice.

there are ways around this with partial simulation of the circuit, but
this will have to do for now.  see the examples directory to see how cyco
was used for the cla-cycle and lines-cycle models.

-25apr98ajb
