Hello vinothkumar,
mem -> refers to deep sleep state. This is the lowest power state our chips can achieve and has the maximum latency. Just for the xtal to power up can take up to 5ms.
standby -> refers to a higher power and lower latency suspend state. In this mode ARM is not power gated, pmic voltages are not lowered, xtal is not disabled etc.
From CCM point of view, both the modes put the chip into STOP mode. But what else is turned off is configured by SW based on the mode requested (standby or mem).
Regards
