17.4.2 Analog Inputs or CVD Sensors Pins

Any CVDANx pin can be mapped to any record by the PINx[6:0] bits in the record register ITCRECx.

The ANSEL register bits for the I/O ports associated with the analog input must be set to configure the corresponding pins as analog pins. A pin is configured as an analog input when the corresponding ANSELx bit = 1. When the ANSELx bit = 0, the pin is set to digital control. The ANSELx bits are set when the device comes out of reset, causing the ADC input pins to be configured as analog inputs by default.

The I/O CVDANx pin is controlled by ITC during ADC conversion or CVD operation. However, when the next CVDANx pin is processed, the control for the idle CVDANx pin is returned to the TRIS and LAT registers of the port.

The TRIS registers switch the pins between the digital inputs and outputs. The port pin that is required for CVD must have its corresponding bit cleared (TRISx = 0) in the specific TRIS register, configuring the pin as an output. It will keep the idle CVD sensor grounded or connected to V_DD depending on LAT register settings.

If the sensor CVDANx pin floats (TRISx = 1) when it is idle between CVD scans, then the robustness will degrade significantly even with a light noise.