Datasheet

772
32142D–06/2013
ATUC64/128/256L3/4U
31.5 Product Dependencies
In order to use the CAT module, other parts of the system must be configured correctly, as
described below.
31.5.1 I/O Lines
The CAT pins may be multiplexed with other peripherals. The user must first program the I/O
Controller to give control of the pins to the CAT module. In QMatrix mode, the Y lines must be
driven by the CAT and analog comparators sense the voltage on the Y lines. Thus, the CAT (not
the Analog Comparator Interface) must be the selected function for the Y lines in the I/O
Controller.
By writing ones and zeros to bits in the Pin Mode Registers (PINMODEx), most of the CAT pins
can be individually selected to implement the QTouch method or the QMatrix method. Each pin
has a different name and function depending on whether it is implementing the QTouch method
or the QMatrix method. The following table shows the pin names for each method and the bits in
the PINMODEx registers which control the selection of the QTouch or QMatrix method.
SMP SMP line (only used for QMatrix) Output
SYNC Synchronize signal Input
VDIVEN Voltage divider enable (only used for QMatrix) Output
Table 31-1. I/O Lines Description
Name Description Type
Table 31-2. Pin Selection Guide
CAT Module Pin
Name
QTouch Method
Pin Name
QMatrix Method Pin
Name
Selection Bit in
PINMODEx Register
CSA0 SNS0 X0 SP0
CSB0 SNSK0 X1 SP0
CSA1 SNS1 Y0 SP1
CSB1 SNSK1 YK0 SP1
CSA2 SNS2 X2 SP2
CSB2 SNSK2 X3 SP2
CSA3 SNS3 Y1 SP3
CSB3 SNSK3 YK1 SP3
CSA4 SNS4 X4 SP4
CSB4 SNSK4 X5 SP4
CSA5 SNS5 Y2 SP5
CSB5 SNSK5 YK2 SP5
CSA6 SNS6 X6 SP6
CSB6 SNSK6 X7 SP6
CSA7 SNS7 Y3 SP7
CSB7 SNSK7 YK3 SP7
CSA8 SNS8 X8 SP8