A hierarchical power supply noise monitoring device and system for very large scale integrated circuits. The noise-monitoring device is fabricated on-chip to measure the noise on the chip. The noise-monitoring system includes a plurality of on-chip noise-monitoring devices distributed strategically across the chip. A noise-analysis algorithm analyzes the noise characteristics from the noise data collected from the noise-monitoring devices, and a hierarchical noise-monitoring system maps the noise of each core to the system on chip.