Abstract: A low-power interface for nonvolatile writeable memory is described. The interface includes an input buffer and an output buffer. The input buffer receives input signals having one of a number of pairs of logic levels. The input buffer is coupled to the nonvolatile writeable memory and coupled to the same power supply as the nonvolatile writeable memory. The input buffer translates the input signals received to the signal level used by the nonvolatile writeable memory. The output buffer is coupled to the nonvolatile writeable memory and is coupled to a different power supply from the input buffer and the nonvolatile writeable memory. The output buffer translates the signals received from the nonvolatile writeable memory to the same signal levels as the input signal. The input buffer and output buffer utilize input/output signals having logic levels compatible with complementary metal-oxide semiconductor (CMOS) technology.

Abstract: A power supply lockout circuit that prevents corruption of nonvolatile writeable memory data is described. The power supply lockout circuit monitors the power supply signals from several power supplies. The power supply lockout circuit locks out commands writing to the nonvolatile writeable memory when any one of the monitored power supply signals coupled to the nonvolatile writeable memory is below a specified signal level. The power supply lockout circuit includes a detector which provides a lockout signal to the nonvolatile writeable memory when a power supply signal is less than a prespecified voltage. The power supply lockout circuit also includes a sampling circuit which provides other lockout signals to the nonvolatile writeable memory when a different power supply signal is less than a reference voltage.