Chips and Technologies, Llc.

Michael G Fung

Justin Wang

A system for masking bits in a configuration. The system has a bus with first and second sets of bit lines. A line from the first set is paired with aline from the second set; the paried lines are coupled to each cell in the configuration register. A logic circuit is connected to each register cell and the corresponding paired lines. Depending upon the state of the bit signal of the second set bit line, the logic circuit passes the bit signal on the first set bit line for loading into the register cell or reloads the bit line signal already in the register cell. In this manner, masking operations in the configuration register can be performed very quickly.

Apparatus for masking data bits

The present invention provides a memory organization scheme for a high-performance memory controller. The memory organization of the present invention combines page mode techniques and interleaving techniques to achieve high-performance. Sequential pages of memory are interleaved between memory banks so that memory accesses which are a page apart will be to two different memory banks. A page is preferably defined by a single row, with 2K columns per row defining the number of bits in a page. Accesses to bits in the same page as a previous access omit the row pre-charge cycle, thus speeding up the memory cycle. Accesses to a separate bank of memory chips from the previous access are likewise speeded up since there is no need to wait for the completion of the cycle in the previous bank before initiating the cycle in the separate bank.

Page interleaved memory access

The present invention provides a memory addressing system that can accommodate multiple size DRAMS. DRAMS of various sizes can be mixed in a variety of ways. The present invention provides a hardware register associated with each pair of banks of DRAMS. This hardware register is programmable to indicate the type of DRAMS that have been inserted in the particular memory banks and to indicate the starting address of the particular set of memory banks. Using this technique, it is necessary to insert the largest memory chips in the first memory bank. Memory chips of either size can be inserted in either set of memory banks and the information in the programmable register is used to control circuitry which appropriately modifies the accessing signals which are sent to the memory system.

Addressing multiple types of memory devices

The present invention provides a memory addressing system that can accommodate multiple size DRAMS. DRAMS of various sizes can be mixed in a variety of ways. The present invention provides a hardware register associated with each pair of banks of DRAMS. This hardware register is programmable to indicate the type of DRAMS that have been inserted in the particular memory banks and to indicate the starting address of the particular set of memory banks. Using this technique, it is not necessary to insert the largest memory chips in the first memory bank. Memory chips of either size can be inserted in either set of memory banks and the information in the programmable register is used to control circuitry which appropriately modifies the accessing signals which are sent to the memory system.

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San Jose, CA, United States of America

Michael G Fung