Method and apparatus for protecting an integrated circuit from erroneous operation

摘要

A data processing system ( 10 ) has an embedded non-volatile memory ( 22 ) that is programmed and erased by use of a high voltage provided by a charge pump ( 78 ). In order to prevent the non-volatile memory ( 22 ) from being inadvertently programmed or erased during low power supply voltage conditions, the charge pump ( 78 ) is disabled and discharged when the power supply voltage drops below a predetermined value. This is accomplished by enabling a low voltage detect circuit ( 110 ) in response to a program or erase operation being initiated. A control register ( 76 ) will provide a high voltage enable signal to the charge pump ( 78 ) only when a power supply valid signal is received. In another embodiment, the low voltage detect circuit ( 110 ) may be enabled by another condition to protect the data processing system ( 10 ) from an authorized access.