Altera Corporation

L Todd Cope

Richard G Cliff

Joseph Huang

James A Watson

Bahram Ahanin

William W Leong

Srinivas T Reddy

Bruce B Pedersen

Cameron R McClintock

David Edward Jefferson

Rina Raman

Kerry S Veenstra

Cameron R Mc Clintock

David Wolk Mendel

Christopher F Lane

Francis B Heile

Craig S Lytle

Chiakang Sung

Wanli Chang

Robert R Bielby

Robert Richard Noel Bielby

Fung Fung Lee

By Louis Leong, Legal Representative

William Leong, Deceased

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 logic array integrated circuit device includes a plurality of regions of programmable logic disposed on the device in a two-dimensional array of intersecting rows and columns. Interconnection conductors are associated with each row and column. The interconnection conductors associated with each row include some that extend continuously along the entire length of the row and some that extend continuously along only the left or right half of the row. To increase the flexibility with which the logic regions can be connected to the row and column conductors, adjacent regions are paired and circuitry is provided for allowing the outputs of each pair to be swapped for driving the row and column conductors. Registers in logic regions can still be used for other purposes when not being used to register the main combinatorial outputs of the logic regions. Many other enhanced features are also provided.

Programmable logic array integrated circuit devices

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 device or field programmable gate array includes an on-chip clock synchronization circuit to synchronize a reference or system clock signal. The clock synchronization circuit is a delay-locked loop (DLL) circuit in one implementation and a phase-locked loop (PLL) circuit in another implementation. The DLL or PLL circuits may be analog or digital. The clock synchronization circuit generates a synchronized clock signal that is distributed throughout the programmable integrated circuit. The synchronized clock signal is programmably connected to the programmable logic elements or logic array blocks (LABs) of the integrated circuit. The clock synchronization circuit reduces or minimizes clock skew when distributing a clock signal within the integrated circuit. The clock synchronization circuit improves the overall performance of the programmable logic integrated circuit.

Programmable logic with on-chip DLL or PLL to distribute clock

Programmable logic integrated circuit with on-chip DLL or PLL for clock

A programmable logic array integrated circuit device has a relatively large block of programmable memory cells in addition to the usual programmable logic modules and the usual programmable interconnection conductor network. In order to simplify the circuitry associated with the large block, and especially the circuitry for addressing that block during programming and/or verification of the device, the address decoder that is normally used to address the block during use of the device to perform logic is also used during programming and/or verification. During programming and/or verification a counter or other similar coded address signal generating circuitry is used to supply address information to the decoder.

Programming and verification address generation for random access memory

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 device includes a plurality of regions of programmable logic disposed on the device in a two-dimensional array of interesting rows and columns. Interconnection conductors are associated with each row and column. The interconnection conductors associated with each row include some that extend continuously along the entire length of the row and some that extend continuously along only the left or right half of the row. To increase the flexibility with which the logic regions can be connected to the row and column conductors, adjacent regions are paired and circuitry is provided for allowing the outputs of each pair to be swapped for driving the row and column conductors. Registers in logic regions can still be used for other purposes when not being used to register the main combinatorial outputs of the logic regions. Many other enhanced features are also provided.

A system (100) for distributing a clock signal to many points on an integrated circuit. The system includes using a delay lock loop with specific digital circuits to accomplish the phase error detection and delay element selection. In one embodiment, two flip-flops are used to detect a phase error. In another embodiment, both macro (202) and micro phase detectors (218) are used and the delay element selection is performed in two stages by using a shift register (210) in a first stage and a counter (220) in a second stage. Another feature of the present invention is, the ability to distribute the reference clock or a synchronized clock to different portions of the circuitry on an integrated circuit. Multiple clock distribution systems are provided which may be selected.

System for distributing clocks using a delay lock loop in a programmable

Growing community of inventors

San Jose, CA, United States of America

L Todd Cope