Altera Corporation

William W Leong

Richard G Cliff

Bahram Ahanin

Cameron R McClintock

Joseph Huang

L Todd Cope

James A Watson

Cameron R Mc Clintock

Chiakang Sung

Wanli Chang

Khusrow Kiani

Janusz K Balicki

Ken-Ming Li

Bezhad Nouban

Benjamin M Cohen

Chengmin Zhang

Gregg B Feigelson

Fung Fung Lee

A programmable logic array integrated circuit has a number of programmable logic modules which are grouped together in a plurality of logic array blocks ('LABs'). The LABs are arranged on the circuit in a two dimensional array. A conductor network is provided for interconnecting any logic module with any other logic module. In addition, adjacent or nearby logic modules are connectable to one another for such special purposes as providing a carry chain between logic modules and/or for connecting two or more modules together to provide more complex logic functions without having to make use of the general interconnection network. Another network of so-called fast or universal conductors is provided for distributing widely used logic signals such as clock and clear signals throughout the circuit. Multiplexers can be used in various ways to reduce the number of programmable interconnections required between signal conductors.

Programmable logic array integrated circuits

A programmable variable depth and width random-access memory circuit is provided. The memory circuit contains rows and columns of memory cells for storing data. A row decoder is used to address individual rows of the memory cells. Column address circuitry receives a column address signal and a width and depth selection signal. A column decoder within the column address circuitry addresses one or more columns of memory cells of the RAM array based on the selected width of the array. The output of the column decoder is routed to the appropriate column or columns of memory cells by a pattern of fixed connections and a group of programmable multiplexers. The number of data output lines to which data signals are provided is determined by the selected width of the RAM array. The output circuitry contains a group of programmable demultiplexers and a routing array having a pattern of fixed connections suitable for passing data signals from the RAM array to the selected number of data output lines.

Variable depth and width memory device

A programmable logic array integrated circuit device has logic regions grouped in blocks, which are in turn grouped in super-blocks. The super-blocks are disposed on the device in a two-dimensional array of intersecting rows and columns. Global conductors are associated with each row and column. Super-block feeding conductors associated with each super-block feed signals from the global conductors to any logic region in the super-block. Local feedback conductors feed back logic region output signals to all logic regions in a block. The super-block feeding conductors are also used to interconnect the logic regions in a super-block so that the global conductors do not have to be used for that purpose.

Programmable logic array integrated circuits with blocks of logic regions grouped into super-blocks

A programmable logic array device has a plurality of logic regions and conductors for conveying signals between the logic regions. Conductors of several different lengths are provided so that most connections between logic regions can be made using conductors which are close to the length required and not wastefully much longer than that length.

Programmable logic array devices with interconnect lines of various lengths

Programmable logic array devices with interconnect lines of various

A programmable logic array integrated circuit has a number of programmable logic modules which are grouped together in a plurality of logic array blocks ('LABs') The LABs are arranged on the circuit in a two dimensional array. A conductor network is provided for interconnecting any logic module with any other logic module. In addition, adjacent or nearby logic modules are connectable to one another for such special purposes as providing a carry chain between logic modules and/or for connecting two or more modules together to provide more complex logic functions without having to make use of the general interconnection network. Another network of so-called fast or universal conductors is provided for distributing widely used logic signals such as clock and clear signals throughout the circuit. Multiplexers can be used in various ways to reduce the number of programmable interconnections required between signal conductors.

A programmable logic array integrated circuit has a number of programmable logic modules which are grouped together in a plurality of logic array blocks ('LABs'). The LABs are arranged on the circuit in a two dimensional array. A conductor network is provided for interconnecting any logic module with any other logic module. In addition, adjacent or nearby logic modules are connectable to one another for such special purposes as providing a carry chain between logic modules and/or for connecting two or more modules together to provide more complex logic functions without having to make use of the general interconnection network. Another network of so-called fast or universal conductors is provided for distributing widely used logic signals such as clock and clear signals throughout the circuit. Multiplexers can be used in various ways to reduce the number of programmable interconnections required between signal conductors. A relatively large block of random access memory ('RAM') may be provided on the device for use as read-only memory ('ROM') or RAM during operation of the device to perform logic. The RAM block is connected in the circuitry of the device so that it can be programmed and verified compatibly with other memory on the device. Thereafter the circuitry of the RAM block allows it to be switched over to operation as RAM or ROM during logic operation of the device.

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San Francisco, CA, United States of America

William W Leong