Abstract: In an advanced metering infrastructure environment, software program statements and/or data may be encrypted. A microcontroller unit may include a first cache configured to store a block of encrypted data obtained from an external memory device. A decryption engine may decrypt the block of encrypted data for storage in a second cache. An address alignment module may be configured to receive input from a program counter and to calculate an offset pointer. The offset pointer may indicate a particular word in the block of decrypted data within the second cache for transmission to an instruction register for use by an application program. An address generator may be configured to receive input from the address alignment module and to indicate a block of data in the external memory device to be loaded into the first cache, to thereby replace the encrypted data sent to the decryption engine.

Abstract: In an advanced metering infrastructure environment, software program statements and/or data may be encrypted. A microcontroller unit may include a first cache configured to store a block of encrypted data obtained from an external memory device. A decryption engine may decrypt the block of encrypted data for storage in a second cache. An address alignment module may be configured to receive input from a program counter and to calculate an offset pointer. The offset pointer may indicate a particular word in the block of decrypted data within the second cache for transmission to an instruction register for use by an application program. An address generator may be configured to receive input from the address alignment module and to indicate a block of data in the external memory device to be loaded into the first cache, to thereby replacing the encrypted data sent to the decryption engine.

Abstract: Disclosed are apparatus and methodology for providing battery protection for devices operating in a battery supplied low-power mode. Micro controller operated devices (such as electricity meters) that may be stored for extended periods after manufacture and before deployment are provided backup battery protection by insertion of an overcurrent operable switch between the battery and the micro controller. A timer causes the micro controller to switch to a normal power mode after a predetermined time period during which no external supply voltage is provided. Normal power mode operation under battery powered supply only will cause the overcurrent switch to open, so as to disconnect the battery from the micro controller. Alternatively, instead of switching the micro controller to a normal power mode after a predetermined time period, the battery powered supply is shorted to ground using an internal switch of the micro controller, to achieve the same result of disconnecting the battery from the micro controller.