Method and Apparatus for On Chip Measurement of Path Sensitive Ring Oscillator
Original Publication Date: 2000-Nov-01
Included in the Prior Art Database: 2003-Jun-20
Disclosed is a technique to measure a Path Sensitive Ring Oscillator (PSRO) within a VLSI chip without an external oscilloscope. PSRO delays are used as indicators to show where a chip lies within the manufacturing process. Generally PSRO delays are measured by one of two methods: 1. Wire the PSRO circuit to a module IO, wire the module IO to a card connector, through a resistor set wire the PSRO connector IO to a high level for circuit activation, attach a probe from an oscilloscope to the connector IO, and observe and record the period of the PSRO waveform. 2. Find the chip number (if visible) and find the manufacturer's data (which may or may not exist) that shows the chip PSRO values for chip numbers.