The i.MX28 can be put into standby mode where the CPU clock is reduced to 64MHz, the internal peripheral clocks are gated, and the DDR2 memory is placed into self refresh mode. In this mode, the DCDC converter outputs continue to run as normal. With the DDR2 memory in self refresh, the system power consumption should be about 8-9mA.
Are there any examples of register settings to accomplish this?
In Linux you can try:
echo standby > /sys/power/state
Press the user keys to wake up the system
Regards,
Fabio Estevam