SCM20100A lowest possible power

I have a custom board with the SCM20100E, a power supply and a USB connector. This plugs into another PCB with RS232 driver IC’s and some 1mA LED’s for indicating data on 3 UARTS. The system is battery powered.

I have the Ethernet PHY disabled and powered off. The clock is set to 50%. The software does nothing more than read in serial data to a buffer and outputs this to an acoustic modem approx every 15 mins.

It draws around 60mA when idle and about 63-65 when processing the serial data.

How can I get this power consumption down much lower? I have thought about going to sleep and waking when it detects serial data but concerned I will lose the first few bytes whilst it wakes up.

I am curious on what you see if the processor was put in sleep or hibernate.

I’ll set it up this weekend and let you know.