Yes, PSoC1 can be used as synchronous demodulator. For synchronous detection, the key is to recover the carrier frequency at the receiver end and mix this with the actual modulated signal. The carrier frequency is recovered using a CT block configured as a Zero Crossing Detector (ZCD). The amplitude modulated signal is passed through a switched capacitor block configured as a unity gain amplifier. The output of ZCD is used to modulate the sign of this switched capacitor amplifier. The output of the switched capacitor block is then passed through a Low Pass Filter to get the demodulated output.