Altera Corporation

Triet M Nguyen

David Edward Jefferson

Martin Langhammer

Keone Streicher

Yi-Wen Lin

Kwan Yee Martin Lee

Andy Louie Lee

David Lewis

Srinivas T Reddy

Paul Leventis

Brian D Johnson

John Henry Bui

Michael Chan

Changsong Zhang

David Wolk Mendel

Vaughn Betz

Christopher F Lane

Cameron R McClintock

Ketan H Zaveri

Hyun Mo Yi

David Cashman

Vikram Santurkar

Giles V Powell

Lu Zhou

Gary Lai

Orang Azgomi

Integrated circuits with memory circuitry are provided. The memory circuitry may include rows of data line segments. Each data line segment may have associated memory cells, a programmable-strength precharge circuit, a latch circuit, a programmable-strength pull-up circuit, and a data line segment buffer. The precharge circuit may include multiple paths that can be switched into use depending on the configuration of programmable bits. The programmable-strength pull-up circuit may include multiple pull-up paths. The number of pull-up paths in use can be configured. The latch circuit may include a latch inverter that enables the programmable latch circuit during precharge operations. During a precharge period, the latch circuit can be disabled to block contending pull-down current and the data line segment buffer can be disabled to avoid crossbar currents.

Programmable precharge circuitry

A programmable logic device includes logic blocks such as a logic array blocks (LAB) that can be configured as a random access memory (RAM) or as a lookup table (LUT). A mode flag is provided to indicate the mode of operation of configuration logic such as a configuration RAM (CRAM) used during partial reconfiguration of a logic block. If the mode flag indicates a design state, the configuration logic associated with the logic block is included in data verification and correction processes. If the mode flag indicates a user defined state, the configuration logic associated with the logic block is excluded from data verification and correction processes. Thus, exclusion and inclusion of portions of a region of configuration logic from data verification and correction processes allow a region of configuration logic to store both a design state and a user defined state without causing deleterious effects.

Reconfigurable logic block with user RAM

A specialized processing block for a programmable logic device includes circuitry for performing multiplications and sums thereof, as well as circuitry for performing floating point operations. The floating point circuitry preferably includes rounding and normalization circuitry. To perform mantissa multiplications, the floating point circuitry preferably relies on the aforementioned multipliers of the specialized processing block.

Specialized processing block for programmable logic device

A specialized processing block for a programmable logic device includes circuitry for performing multiplications and sums thereof, as well as circuitry for rounding the result. The rounding circuitry can selectably perform round-to-nearest and round-to-nearest-even operations. In addition, the bit position at which rounding occurs is preferably selectable. The specialized processing block preferably also includes saturation circuitry to prevent overflows and underflows, and the bit position at which saturation occurs also preferably is selectable. The selectability of both the rounding and saturation positions provides control of the output data word width. The rounding and saturation circuitry may be selectably located in different positions based on timing needs. Similarly, rounding may be speeded up using a look-ahead mode in which both rounded and unrounded results are computed in parallel, with the rounding logic selecting between those results.

Integrated circuits with memory elements are provided. The memory elements may be arranged in an array. Data lines may be used to load data into the memory elements and may be used to read data from the memory elements. The memory elements may be used to store configuration data on a programmable logic device integrated circuit. Each memory element may have an output that supplies a programmable transistor gate with a static control signal. Data reading circuitry may be coupled to each data line to read data from an addressed memory element on that data line. The data reading circuitry for each data line may include a precharge transistor and an output latch. The output latch may contain cross-coupled inverters. An inwardly-directed inverter in the output latch may have a pull-up transistor that is connected in series with a current source.

Memory elements with leakage compensation

A specialized processing block for a programmable logic device incorporates a fundamental processing unit that performs a sum of two multiplications, adding the partial products of both multiplications without computing the individual multiplications. Such fundamental processing units consume less area than conventional separate multipliers and adders. The specialized processing block further has input and output stages, as well as a loopback function, to allow the block to be configured for various digital signal processing operations.

Adder/rounder circuitry for use in a programmable logic device computes a rounded sum quickly, and ideally within one clock cycle. The rounding position is selectable within a range of bit positions. In an input stage, for each bit position in that range, bits from both addends and a rounding bit are processed, while for each bit position outside that range only bits from both addends are processed. The input stage processing aligns its output in a common format for bits within and outside the range. The input processing may include 3:2 compression for bit positions within the range and 2:2 compression for bit positions outside the range, so that further processing is performed for all bit positions on a sum vector and a carry vector. Computation of the sum proceeds substantially simultaneously with and without the rounding input, and rounding logic makes a selection later in the computation.

Adder-rounder circuitry for specialized processing block in programmable logic device

A clock network for an integrated circuits includes a first set of lines configured to distribute clock signals to a first section of the integrated circuit. The clock network also includes a second set of lines configured to distribute clock signals to a second section of the integrated circuit separately from the first section of the integrated circuit.

Programmable clock network for distributing clock signals to and between first and second sections of an integrated circuit

A programmable logic device and associated method is provided with repairable regions. In one aspect, general routing interconnect lines are segmented within repairable regions. In another aspect, IO bus lines and associated circuitry are provided that accommodate redundancy in a staggered segmented architecture. In another aspect, a dedicated routing architecture between particular logic regions accommodates shifting to define and utilize repairable regions. Principles of other aspects are illustrated and described in the context of several exemplary embodiments of aspects of the invention.

Programmable logic device with redundant circuitry

In one aspect, flexible routing resources provided are comprising an arrangement of staggered line segments on a periphery of an electronic device. In another aspect, I/O bus lines a re coupled to receive signals from and to provide signals to other bus lines, core routing, and I/O circuitry, thus facilitating the use of the I/O bus for a variety of routes that may include I/O-to-core, core-to-I/O and core-to-core routes. In another aspect, a length of I/O bus lines is optimized for speed over long signal routes with high fanout. In another aspect, the loading effects of high fanout are minimized by using a plurality of tapping buffers to couple lines to both core routing and to I/O circuitry. In another aspect, a spiraling technique is provided that allows a continuous bus having line segments of consistent length whether or not the number of I/O blocks is an integral multiple of the selected logical length for line segments.

Flexible I/O routing resources

Methods and apparatus for segmenting lines in programmable logic devices having redundancy circuitry. A programmable logic device includes a first plurality of logic array blocks. The first plurality of logic array blocks includes a first logic array block and a second logic array block, a first programmable interconnect line coupled to a segmentation buffer and programmably coupled to the first logic array block, and a second programmable interconnect line coupled to the segmentation buffer and programmably coupled to the second logic array block. The segmentation buffer is capable of selectively providing an open circuit between the first programmable interconnect line and the second programmable interconnect line, a buffer driving signals from the first programmable interconnect line to the second programmable interconnect line, or a buffer driving signals from the second programmable interconnect line to the first programmable interconnect line.

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San Jose, CA, United States of America

Triet M Nguyen