Inventors:
Eric E. Edwards - Albuquerque NM, US
Charles D. Laverty - Albuquerque NM, US
Assignee:
Xilinx, Inc. - San Jose CA
International Classification:
G11C 5/14
US Classification:
365226, 365228, 365229, 365206
Abstract:
A method and apparatus is provided to enhance the power-up sequence for integrated circuits (ICs) that contain memory cells having single-ended data inputs with no local reset function. During a power-up sequence, the logic levels that are applied to the data, address, and power inputs of the memory cell are restricted to particular magnitudes by a power-on reset (POR) state machine. First, the data input of the memory cell is held to a logic low value while an address signal of the memory cell is allowed to be asserted to a logic high value in conjunction with activating a power supply that provides operational power to the IC. Next, the address input to the memory cell ramps up to full logic high value, while the regulated power supply to the memory cell array is held low. The regulated power supply then ramps up to an operational level to bias the memory cell into a known logic state.