Hello Everyone,

I am trying to evaluate the SAM9G35 part for my next project. The product requires the need to have a rich TFT LCD display. But when the product is in "user idle" mode a.k.a. when the user is not interacting with it, the LCD will display a static image and dim the backlight.

During this state, I would like to reduce the power consumption by turning off the ARM core and all other peripherals except LCD, Touch (Pen Detect), and of course the memory interface. I am hoping that I can use the DMA built into the LCD controller to constantly refresh the screen at a frequency set by the pixel clock and the resolution and wake the processor up only when a Pen detect is recorded.

Is there a way to do the same? The sequence in my mind is..
1. X sec have passed since the last user interaction, so place a static image in the memory (frame buffer)
2. Initiate DMA transfer mode
3. Setup pen detect interrupt to wake the processor.
3. Put the ARM core in Idle mode (stop the clock) and also put all unused peripherals to Idle.
4. Wait for interrupt while the DMA continues to update the LCD at a fixed rate.

Is this possible and have people already used such scheme? (I'm sure they have).

Thank you in advance to all your replies and patience .
Regards

Santhosh