Testing an integrated circuit receiver in a package using a varying analog voltage

Examples herein describe techniques for testing a receiver interface on a die. In one embodiment, the die includes tester circuitry which includes a digital to analog convertor (DAC) which outputs an analog test signal to a selector circuit (e.g., a multiplexer) which forwards the analog test signal to a receiver. By varying the analog test signal, the tester circuitry can identify one or more trip points corresponding to the receiver. That is, by monitoring the output of the receiver, a testing application can determine when the output of the receiver switches states thereby indicating that the analog test signal at the input of the receiver corresponds to the trip point of the receiver. In this manner, internal circuitry (e.g., the tester circuitry) can be used to test a receiver interface that may otherwise be inaccessible.