Disclosed is an across-chip temperature sensing circuit and an associated method that can be used to profile the across-chip temperature gradient. The embodiments incorporate a plurality of phase change elements distributed approximately evenly across the semiconductor chip. These phase change elements are programmed to have essentially the same amorphous resistance. Temperature-dependent behavior exhibited by each of the phase change elements individually is compared to a reference (e.g., generated by a discrete reference phase change element, generated by another one of the phase change elements, or generated by an external reference) in order to profile the temperature gradient across the semiconductor chip. Once profiled, this temperature gradient can be used to redesign and/or relocate functional cores, to set stress limits for qualification of functional cores and/or to adjust operating specifications of functional cores.