Collaboration diagram for Device Pin Configuration:

When the device comes out of RESET, all general purpose inputs/outputs (GPIO) are configured as high-impedance inputs. Sample and hold (S&H) circuits of ADC inputs are active and digital functions are blocked. Depending on the application, this may or may not be desired. Hence, this routine is used to set a different default state at startup where GPIOs are high impedance inputs but all analog functions are disabled.