An arbitrary noise generator (ANG) is based on time-series charging of divided parasitic capacitance (TSDPC) and emulates power supply noise generation in a CMOS digital circuit. A prototype ANG incorporates an array of 32 x 32 6-bit TSDPC cells along with a 128-word vector memory and occupies 2 x 2 mm2 in a 65 nm 1.2 V CMOS technology. Digital noise emulation of functional logic cores such as register arrays is demonstrated with chip-level waveform monitoring at power supply, ground, as well as substrate nodes.