An I/O pin mapping module integrated on a microcontroller chip allows any microcontroller circuit node connected to the I/O pin mapping module to be mapped to any microcontroller I/O pin connected to the I/O pin mapping module. The size of the I/O pin mapping module can be customized prior to integration in accordance with the number of circuit nodes and I/O pins to be connected thereto. The I/O pin mapping module is programmable and can be described in a high level language to create a generic module that can be used in different microcontroller families, as well as in other types of integrated circuit chips.