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BF548 wake-up from hibernate with Keypad/Rotary

Question asked by mmccar on Jan 4, 2011
Latest reply on Apr 8, 2011 by Prashant

I am trying to get a BF548 processor in the BF548 EZ-KIT Lite to wake up from the hibernate state from keypad or rotary counter activity, but have been unable to get this to work. I can successfully wake up from both RTC and USB events. Does anyone have any tips how to do this?

 

From the documentation, I should set the ROTWE and KPADWE bits in the VR_CTL register, and for the keypad, the Row pins should be set to GPIO mode (0 in PORTx_FER register) and the output set to high.

 

Checking the physical pins, I can see that the keypad row pins are high during hibernate and are correctly pulled low when a key is pressed. Similarly, the rotary pins exhibit the correct behaviour. I also believe I have the switch settings on the EZ-KIT Lite board setup correctly (have tried other combinations anyway).

 

A further note is that I am not using the bfrom_SysControl function to enter hibernate as the documentation recommends, but writing to VR_CTL directly. If I use this function, hibernate is entered, but on wakeup, the VDDINT voltage climbs slowly to 2.5V and the device does not boot correctly.

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