Many integrated circuits (ICs) (also referred to herein as “dies”) are coupled to external resistors (e.g., discrete components) since variation in the resistance values of external resistors is typically better controlled than on-die resistors.  That is, because of variations in the fabrication process used to create on-die resistors, their resistance values can fluctuate as much as 10-15% depending on the process corner.  Thus, instead of fabricating on-die resistors, the die may rely on external resistors to perform operations which require accurate resistance values. 
However, there are several disadvantages with using external resistors.  For example, the external resistor take up valuable space in a package.  Further, the die needs to use at least one I/O element (e.g., an input/output (I/O) pin) to couple to the external resistor which leaves one less I/O element that can be used by the die to perform another function.  Put differently, the system may require that the die include a dedicated I/O pin that couples the die to the external resistor.