Xilinx, Inc.

Altera Corporation

Triscend Corporation

Andreas Papaliolios

Brian Fox

Richard G Cliff

Srinivas T Reddy

Chiakang Sung

Kerry S Veenstra

Rina Raman

Richard Shaw Terrill

Steven Winegarden

Edmond Y Cheung

Robert Richard Noel Bielby

Sridhar Krishnamurthy

Jean-Didier Allegrucci

Bart Reynolds

Fung Fung Lee

Arye Ziklik

Danesh Tavana

Robert R Bielby

Stanley S Yang

The present invention allows a user to customize the configuration sequence of a configurable system on a chip (CSoC), thereby adding considerable flexibility to the configuration process. The present invention also provides certain features, transparent to the user, which optimize system resources and ensure the correct initialization of the CSoC. The CSoC leverages an on-chip central processing unit (CPU) to control the configuration process of the configurable system logic (CSL). Advantageously, the CSL configuration memory cells as well as other programmable locations in the CSoC are addressable as part of a system bus address space. The system bus is a multi-use structure that can be used for both configuring and reading of memory cells. In this manner, the CSoC optimizes system resources.

Configuration in a configurable system on a chip

The I/O circuit of the present invention provides optimal flexibility and performance using a number of different structures and methods. The present invention provides a signal follower circuit for an input pad. In one embodiment, the output buffer is capable of injecting a constant onto a pad during reconfiguration of a configurable system logic circuit. The present invention also provides a circuit for generating a programmable data propagation delay, thereby guaranteeing zero hold time for an arbitrary input register. Zero hold time is accomplished by allowing the user to optimally characterize clock delay to a given input/output circuit. The present invention also provides fast switching between input pads, thereby minimizing data propagation delay between the input pads. Additionally, the present invention reduces time spent in production product test by facilitating the testing of multiple routes with one test configuration. A circuit expanding the number of data input channels available to system routing is provided. Lastly, a plurality of identical input/output block tiles (IOBTs) is disclosed, thereby enabling each I/O circuit to provide the same signals regardless of the IOBTs location in the I/O circuit.

Input/output circuit with user programmable functions

The configurable processor system includes a processor, an internal system bus, and a programmable logic all interconnected via the internal system bus, on a single integrated circuit.

Configurable processor system unit

Programmable logic array devices are programmed from programming devices in networks that facilitate programming any number of such logic devices with programs of any size or complexity. The source of programming data and control may be a microprocessor or one or more serial EPROMs, one EPROM being equipped with a clock circuit. Several parallel data streams may be used to speed up the programming operation. A clock circuit with a programmably variable speed may be provided to facilitate programming logic devices with different speed characteristics. The programming protocol may include an acknowledgment from the logic device(s) to the programming data source after each programming data transmission so that the source can automatically transmit programming data at the speed at which the logic device is able to accept that data.

Techniques for programming programmable logic array devices

A method and apparatus for a power-on reset system is provided. The power-on reset system comprises a voltage sense circuit for determining whether a voltage level is above a threshold and a write/rewrite verifier circuit for determining whether the voltage level is high enough to write to and rewrite a memory cell content. A power-on reset pulse emitted by the power-on reset system if the voltage level is above the threshold and high enough to write to and rewrite the memory cell. For one embodiment, this is system generates an initial POR pulse upon power-up but can thereafter be selectively disabled and consume zero power.

Method and apparatus for a power-on-reset system

An output driver to reduce totem pole current is provided. The output driver comprises a first delay element outputting a delayed first driver signal, and a first selection unit receiving as an input the first driver signal and the delayed first driver signal. The output driver further comprises a second delay element outputting a delayed second driver signal and a second selection unit receiving as an input the second driver signal and the delayed second driver signal. A selection signal for the first selector is the first driver signal, and the selection signal for the second selector is an inverted first driver signal, such that a path that is not presently driving is switched off first, prior to the opposing driver being turned on.

Output pre-driver for reducing totem pole current

Programmable logic array devices are programmed from programming devices in networks that facilitate programming any number of such logic devices with programs of any size or complexity. The source of programming data and control may be a microprocessor or one or more serial EPROMs, one EPROM being equipped with a clock circuit. Several parallel data streams may be used to speed up the programming operation. A clock circuit with a programmably variable speed may be provided to facilitate programming logic devices with different speed characteristics. The programming protocol may include an acknowledgement from the logic device(s) to the programming data source after each programming data transmission so that the source can automatically transmit programming data at the speed at which the logic device is able to accept that data.

Growing community of inventors

Sunnyvale, CA, United States of America

Andreas Papaliolios