low power mode in mini6410

Dear friendlyarm users

I'm using mini6410 in carpc system. It is located in car which is not
accessible after installation. So we can not turn it off/on manually and it
should go low power modes automatically.  we use COM1,2 ports in our
project, it is possible to use data serial port as an event for low power
mode. 

I mean for example when we don't receive any data from serial port for 20
minutes Mini6410 should go low power mode and as soon as any data receive
from serial port it should go to normal mode.

Would you mind please tell me how we can run this feature in this unit?

Regards,

As I have no specific experience on the uP used in the 6410 I can only
suggest a general method.

The UART will have interrupts that can signal when there is information in
the RX (receive) buffer (Receive buffer data ready?).  Maybe, there is some
way you can wake the uP out of sleep mode using a RX interrupt.

What does the datasheet have to say about power management on the uP used
in the mini6410?

For the S3C2440 (mini2440) it talks about:
****
The wakeup from SLEEP mode can be issued by the
EINT[15:0] or by RTC alarm interrupt.

Signaling EINT[15:0] for Wakeup
The S3C2440A can be woken up from SLEEP mode only if the following
conditions are met.
a) Level signals (H or L) or edge signals (rising, falling or both) are
asserted on EINTn input pin.
b) The EINTn pin has to be configured as EINT in the GPIO control register.
c) nBATT_FLT pin has to be H level. It is important to configure the EINTn
in the GPIO control register as an
external interrupt pins, considering the condition a) above.
Just after the wake-up, the corresponding EINTn pin will not be used for
wakeup. This means that the pin can be
used as an external interrupt request pin again.
****

I don't see a process for waking up from sleep on UART interrupts.

Maybe you could wake up from sleep by changing a port as in a) when you get
RX data in your software.

Just some thoughts.