PIC32MX3XX_1 Datasheet, PDF (34/208 Pages) Microchip Technology – High-Performance, General Purpose and USB 32-bit Flash Microcontrollers

PIC32MX3XX/4XX
2.9 Configuration of Analog and
Digital Pins During ICSP
Operations
If MPLAB ICD 2, ICD 3 or REAL ICE is selected as a
debugger, it automatically initializes all of the A/D input
pins (ANx) as “digital” pins by setting all bits in the
ADPCFG register.
The bits in this register that correspond to the A/D pins
that are initialized by MPLAB ICD 2, ICD 3 or REAL
ICE, must not be cleared by the user application
firmware; otherwise, communication errors will result
between the debugger and the device.
If your application needs to use certain A/D pins as
analog input pins during the debug session, the user
application must clear the corresponding bits in the
ADPCFG register during initialization of the ADC
module.
When MPLAB ICD 2, ICD 3 or REAL ICE is used as a
programmer, the user application firmware must
correctly configure the ADPCFG register. Automatic
initialization of this register is only done during
debugger operation. Failure to correctly configure the
register(s) will result in all A/D pins being recognized as
analog input pins, resulting in the port value being read
as a logic ‘0’, which may affect user application
functionality.
2.10 Unused I/Os
Unused I/O pins should not be allowed to float as
inputs. They can be configured as outputs and driven
to a logic-low state.
Alternately, inputs can be reserved by connecting the
pin to VSS through a 1k to 10k resistor and configuring
the pin as an input.
DS61143G-page 34
© 2010 Microchip Technology Inc.