Abstract: VLSI and ULSI devices like microprocessors and DRAM devices are prone to large scale theft from factories and warehouses. A proposed method of reducing the theft incorporates a small amount of non-volatile flash memory in these devices. The flash memory contains password, device serial number and user identification information. On power-up, the device initiates an encrypted password verification session through a standard interface. If the user supplied password fails, the device's operational ports (any data or control output buses) are tri-stated, thus making the device unusable. The device serial number and user identification information are useful in determining ownership of stolen devices when recovered.

Abstract: A memory system (30), comprised of a plurality of banks (32.sub.0 -32.sub.7) of DRAM devices (10) is controlled by a memory controller (34) that not only determines the presence and density of the DRAM devices upon power-up, but also controls their addressing during normal operation. The memory controller addresses the DRAM devices in each bank by providing each with a complete row address and a complete column address that simultaneously specifies the row and column address for the condition when the DRAM device is symmetric and asymmetric. In this way, the controller can accommodate both symmetric and asymmetric DRAM devices in the same bank.

Abstract: An electronic circuit (10) for controlling and testing up to eight banks (12) of RAMs (14.sub.1 -14.sub.n) includes a controller portion (20) for controlling accessing of the RAM banks to permit read and write operations to be carried out, and for initiating testing of the RAMs as well. The circuit (10) also includes a data path portion (22) for detecting parity errors in the data written to and read from the RAMs as well as for detecting errors which occur during testing initiated by the control portion. An interface portion (24) may also be provided to allow test commands, status information and error data to be communicated to and from the circuit (10) across a four-wire boundary scan bus.