strange simulation curves

i use spectre (mmsim 7.1 version) for my circuit simulation. but when i see my simulation results, i find that the curve is sawtooth shape in the whole half clock period (Tclock/2, and my circuit has many switches), it looks like that it will never settle at all. i'm confused.

for ex: one part of my circuit can be seen as the folloiwng path:

switch S1, cap C1, Buffer1, switch S2. first, S1 closed, signal is sampled to C1, and then, after a period of time, S2 closed, the sampled signal in C1 transfers to the following circuit, such as a buffer, too.

in this example, the signal in C1 and after S2 are all sawtooth shape during the whole period, so i don't how to find the exact signal value at the end of every clock phase.

maybe my question is not very clear, but pls help me. thanks all.

Added after 4 minutes:

pls tell me the reasons, which reason can cause the problem, from circuit itself or simualtion method or others? and how to solve the problem.

Have you tried to turn on the "skipdc" option?

i don't, what is the role of turning on the "skipdc" option? turn on or turn off the "skipdc" option, is there any difference?

i tried to turn on the "skipdc" option, but it doesn't work. any other advice?

Change the transient method to something besides "TRAP"
or "TRAPGEAR2"; trapezoidal integration is not damped
enough to squash the numerical residues and sawtoothing
is common. Try GEAR or EULER (the latter being almost
too well damped, great for getting a quiet result but may
be unrealistically so, just as TRAP is unrealistically noisy).

You can also select "conservative" tolerances and drive
down (if not out) the behavior.

I think It is a matter of simulation step. Choose a smaller step in the tran option.

thanks all, i will try it again.