According to the user guide Sony CFD S70, if you press the Play/Pause button the cd should stop the playback audio and then when you press the Play/Pause button once more it should start from where it left off.
This does not necessarily mean that the disc will stop spinning. A lot of CD players act this way, i.e. playback audio stops but disc keeps on spinning. It shouldn't harm the disc drive motor or the CD, as long as you don't leave it in this state for an excessively long time and it actually begin to wear out the motor drive).
If you press the Stop button to stop playback and then press the Play/Pause button after playback has stopped then playback will commence from the beginning of the track you were last on.
If you press the Stop button twice or turn off the power then (when the power is turned on again) the playback will begin from the start of the CD, unless you select a track by using the Fast Forward button.
Hopefully this is of some help