Circuit structure and method for digital integrated circuit performance screening

Abstract

Disclosed is a semiconductor chip with a digital integrated circuit, such as a memory device (e.g., static random access memory (SRAM) arrays, dynamic random access memory (DRAM) arrays, content addressable memory (CAM) arrays, etc), that can be selectively operated in either a functional mode or in a performance screening mode. In the functional mode, a first signal supplied by an external signal generator is used to activate a first device in the circuit and, in response, a second device in the circuit outputs a data output signal. In the performance screening mode, a second signal is internally generated by an internal signal generator based on the data output signal. This second signal is then used to activate the first device in the circuit and, in response, the second device outputs the data output signal. Thus, in the performance screening mode, the digital integrated circuit is effectively converted into a performance screen ring oscillator (PSRO), the output of which can be monitored to determine whether performance criteria for the digital integrated circuit are met.