I would like some specifications/requirements for using an external 32 kHz clock to drive the 32 kHz clock input on a AT91M55800 uP. This would include:
Minimum and maximum drive level over all conditions
Recommended external drive impedance
AC or DC coupled?
Proper injection point for external oscillator (I am assuming XIN32)

Also would like to have a reference to where and in what Atmel document that I can find this information.

Thanks.

Hi Rgroh,

The slow clock oscillator of the AT91M55800A is the default oscillator at power-up. In this case, it is started and is not in bypass mode (this oscillator has a bypass mode but it is not used in this condition into the AT91M55800A). In sum, IT HAS NOT BE USED WITH AN EXTERNAL CLOCK SIGNAL TO ITS XIN32 INPUT PIN. It is a low power oscillator which is working in linear domain. Having an external clock to XIN32 level can lock its startup while this signal remains on XIN32 !!

Thank you for the information. We have rejected the idea in any event due to uncertainty and lack of any specific information. Your comments make our decision look even better! We have simply decided to use a long reset pulse and live with the increased bootup time.