Abstract: Storage protection keys and system data share the same physical storage. The key region is dynamically relocatable by firmware. A Configuration Array is used to map the absolute address of the key region in to its physical address. The absolute address of keys can be fixed even though the physical location of the keys is relocated into a different region. A triple-detect double correct ECC scheme is used to protect keys. The ECC scheme is different from regular data in the storage and can be used to detect illegal access. Extra firmware and hardware is also designed to restrain customer's applications from directly accessing keys. With the key region being relocatable, the firmware could move the key region away from a known faulty area in a memory to improve system RAS. We also achieved the commonality objective that key memory device can use the same memory devices with other server systems that do not use keys.

Abstract: A DDR SDRAM DIMM for a mainframe main storage subsystem has a plurality of DDR SDRAMs on a rectangular printed circuit board having a first side and a second side, a length (152 MM=6 inch) between 149 and 153 millimeters and optimized at 149.15 mm or 151.35 mm in length and first and second ends having a width smaller than the length; a first plurality of connector locations on the first side extending along a first edge of the board that extends the length of the board, a second plurality of connector locations of the second side extending on the first edge of the board, a locating key having its center positioned on the first edge and located between 80 mm and 86 mm and optimized with a locating key 1.5 mm wide centered at 81.58 or 85.67 mm from the first end of the board and located between 64 and 70 mm and optimized with the locating key centered at 67.58 or 65.675 from the second end of the board.

Abstract: A system for monitoring hardware events in a computer system implements a hardware event monitor of control registers and has programmable generic fields which can be internally or externally programmed for monitoring events ranging from simple operations to complex event sequences. Using programmed criteria incorporated into the hardware event monitor to events within said computer system are monitored by initiating successive compares of programmed criteria with processing events. The hardware event monitor can trigger external actions upon successful detection of compares indicating that all criteria programmed into the hardware event monitor have been achieved. None of the bits within the Control Registers are mutually exclusive which allows multiple scenarios to be programmed.