Sun Microsystems, Inc.

Jay C Robinson

Clement Fang

Tayung Wong

John Carrillo

Mark W Insley

Nagaraj P Mitty

David Jeffrey

Stephen Berry

Nikhil Vaidya

A memory expansion module with stacked memory packages. A memory module is implemented using stacked memory packages. Each of the stacked memory packages contains multiple memory chips, typically DRAMs (dynamic random access memory). The memory may be organized into multiple banks, wherein a given memory chip within a stacked memory package is part of one bank, while another memory chip in the same package is part of another bank. The memory module also includes a clock driver chip and a storage unit. The storage unit is configured to store module identification information, such as a serial number. The storage unit is also configured to store information correlating electrical contact pads on the module with individual signal pins on the stacked memory packages. This may allow an error to be quickly traced to a specific pin on a stacked memory package when an error is detected on the memory bus by an error correction subsystem.

Memory expansion module with stacked memory packages and a serial storage unit

A memory expansion module including multiple memory banks and a bank control circuit is disclosed. In one embodiment, a memory module includes a printed circuit board with a connector edge adapted for insertion in an expansion socket of a computer system. Mounted upon the circuit board is a plurality of memory chips, typically Dynamic Random Access Memory (DRAM) chips, which make up an upper bank and a lower bank of memory. A buffer circuit is mounted upon the printed circuit board, for the purpose of driving address signals, Column Address Strobe (CAS) signals, and write enable signals to each of the memory chips. Also mounted upon the printed circuit board is a bank control circuit, which is coupled to the memory chips. An address signal is used as a bank selection input to the bank control circuit, which will drive Row Address Strobe (RAS) signals to the memory chips of the selected memory bank. The bank control circuit is further configured to drive RAS signals to both banks simultaneously during CBR (CAS before RAS) refresh operations, which occur when a CAS signal is asserted before a RAS signal.

Memory expansion module including multiple memory banks and a bank control circuit

The invention provides a method and apparatus for a memory device interface between a memory device and a CPU as well as the dimensions of the memory device. An electric circuit of the present invention has one-hundred-twenty pins along the length of the housing. The housing of the memory device has a length of approximately 85.6 mm and a width of approximately 54.0 mm. The left and right side socket interface portions of the housing have a minimum width of approximately 3.3 mm. The top socket interface portion has a maximum thickness of approximately 3.5 mm and a minimum height of approximately 3.0 mm. The bottom socket interface portion has a maximum thickness of approximately 5.0 mm and a minimum height of approximately 10.5 mm. Furthermore, the memory device interface portion of the present invention includes at least one pin which provides access to an address signal which indicates a memory array address location within the memory device. The interface portion also includes at least one pin which provides access to a data signal. Additionally, the interface portion includes a row address strobe signal which indicates that the address signal provided to the memory device is a row address, similarly at least one pin providing access to a column address strobe signal is included in the interface portion of the present invention. This column address strobe signal indicates that the address signal provided to the memory device is a column address. Further, at least one pin providing access to a memory write signal and at least one pin providing access to a memory output enable signal are included in the interface portion. Finally, the memory device interface of the present invention provides access to a power supply and to ground.

Method and apparatus for high density sixteen and thirty-two megabyte

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Sunnyvale, CA, United States of America

Jay C Robinson