Display ink rendering during system sleep

A display controller for a touchscreen display, the display controller comprising:

• an image data input to which image data is provided;
• a pixel control output at which pixel control data is provided for the touchscreen display, the pixel control output being coupled to the image data input to define an image data processing pipeline;
• a memory disposed along the image data processing pipeline and configured to store frame data derived from the image data;
• a touchscreen input at which touchscreen data indicative of an ink stroke is received;
• a rendering engine disposed along the image data processing pipeline, the rendering engine comprising a processor, the processor coupled to the touchscreen input to process the touchscreen data to generate ink image data from the touchscreen data;
• and
• a bypass data path via which the image data is provided to the rendering engine when a processor configured to generate the image data resides in a sleep mode,
• wherein the rendering engine is coupled to the memory to store the ink image data in the memory when the image data is not received via the image data input such that the frame data stored in the memory comprises the ink image data and that the pixel control data is representative of the ink stroke.

A method of controlling a display of an electronic device, the method comprising:

• detecting a trigger event while a processor of the electronic device resides in a sleep mode, wherein detection of the trigger event activates a display controller for the display;
• obtaining touchscreen data indicative of an ink stroke by generating the touchscreen data via a digitizer of the electronic device;
• sending the touchscreen data from the digitizer to the display controller via a bypass data path via which the touchscreen data bypasses the processor of the electronic device;
• generating, via an ink rendering engine of the display controller, ink image data from the touchscreen data;
• storing the ink image data as frame data in a memory of the display controller;
• and
• generating, via the display controller, pixel control signals representative of the ink image data.