The clock for the CAT module, CLK_CAT, is generated by the Power Manager (PM). This clock is turned on by default, and can be enabled and disabled in the PM. The user must ensure that CLK_CAT is enabled before initializing the QTouch Library.
QMatrix operations also require the CAT generic clock, GCLK_CAT. This generic clock is generated by the System Control Interface (SCIF), and is shared between the CAT and the Analog Comparator Interface. The user must ensure that the GCLK_CAT is enabled in the SCIF before using QMatrix functionality. For proper QMatrix operation, the frequency of GCLK_CAT must be less than one fourth the frequency of CLK_CAT.
For QMatrix operation, the Analog comparators channels are used (using the ACIFB interface) depending on the Y Lines enabled.
The QMatrix method acquisition using the CAT module requires two Peripheral DMA channels that must be provided by the application.