Measurements circuitry and method for generating an oscillating output signal used to derive timing information

Abstract

A measurement circuit and method is provided for generating an oscillating output signal used to derive timing information. The measurement circuit includes a ring oscillator having a plurality of unit cells, where each unit cell comprises at least a storage element whose output signal is used to determine a clock input signal for an adjacent unit cell within the ring oscillator. Control circuitry performs a control operation to control either a set function or a reset function of the storage element in each of the unit cells, in dependence on set or reset signals input to the control circuitry. Oscillation initiation circuitry is used to assert a clock input signal to the storage element in a first unit cell in order to initiate generation of the oscillating output signal, and the control circuitry then performs the control operation in order to control a value of the output signal of the storage element in each unit cell so as to cause the oscillating output signal to be maintained. Such an approach provides a particularly simple and efficient mechanism for deriving timing information for various circuit blocks that include a storage element.