K70 interfaces all the signals needed for the LCD.
You can update data at any rate you want, but the LCD must be refreshed using 50 or 60 Hz to prevent decay of charges in cells/
Remember that LCDs are like an analog matrix of memory charges that contain a voltage to indicate how much brightness of light is allowed to transmit thru ( on transmissive TFT's) or reflect ( on reflection types) using a diffused light source.
THe K70 will take data and convert it analog with DAC and send to display as an analog voltage. If the scanning stopped, there is a risk that the charge would become trapped or decay to a different value and display as distortion, so refresh rates are standardized. But you dont have to keep sending data from RAM, I believe.
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