Altera Corporation

Roger May

Andrew Martyn Draper

Edward H Flaherty

Andrew Crosland

Mark Dickinson

Paul Metzgen

Neil Kenneth Thorne

Igor Kostarnov

James Tyson

Adam Titley

Stephane Cauneau

Stephane Caneau

A programmable integrated circuit may implement a safety function in a first region and a non-safety function in a second region of the programmable integrated circuit. The safety function may require that periodic tests verify the integrity of the programmable integrated circuit during safety test intervals. For this purpose, the programmable integrated circuit may halt the operation of the safety function, partially reconfigure the first region by loading a test function, and execute the test function, while the non-safety function in the second region continues to operate. In the event that the test function executed successfully without finding any defects, the programmable integrated circuit may partially reconfigure the first region by re-loading the safety function. Additional tests may be performed if the test function detected problems with the integrity of the programmable integrated circuit.

Testing an integrated circuit in user mode using partial reconfiguration

A video processing device has an input for receiving video data, at least one processing circuit, for generating processed video data from the received video data, and a memory, for receiving the processed video data. An output circuit reads the processed video data from the memory, and generates frames of data including at least the processed video data. In order to be able to operate with an output clock frequency that may differ from the ideal output clock frequency, it is possible to vary the frame size, that is, the number of pixels of data in a frame. If an amount of processed video data stored in the memory exceeds an upper threshold, then the frame size can be reduced by reducing the number of pixels of blanking data in the output frame, thereby increasing the rate at which data is read from the memory. Conversely, if an amount of processed video data stored in the memory is lower than a lower threshold, then the frame size can be increased by increasing the number of pixels of blanking data in the output frame, thereby reducing the rate at which data is read from the memory.

Video processing architecture

Methods and apparatus for programmable logic devices including embedded processors having a dual-port SRAMs. A programmable logic integrated circuit includes a programmable logic portion having a plurality of logic elements, programmably configurable to implement user-defined combinatorial or registered logic functions, and an embedded processor portion coupled to the programmable logic portion. The embedded processor portion includes a processor, and a memory block coupled to the processor. The memory block includes a first plurality of memory cells for storing data, a second plurality of memory cells for storing data, a first port coupled to the first and second pluralities of memory cells, a second port coupled to the first and second pluralities of memory cells, and an arbiter coupled to the first port and the second port. When the second port is accessing the first plurality of memory cells, the arbiter prevents the first port from accessing the first plurality of memory cells, and when the second port is accessing the first plurality of memory cells, the arbiter allows the first port to access the second plurality of memory cells.

Embedded processor with dual-port SRAM for programmable logic

A SDRAM controller prioritizes memory access requests to maximize efficient use of the bandwidth of the memory data bus, and also gives different priorities to access requests received on its different inputs. The SDRAM controller has multiple inputs, at least one of which allows connections to multiple bus master devices. The SDRAM controller forms a queue of bus access requests, based amongst other things on a relative priority given to the input on which a request is received. When a request is received on an input which allows connections to multiple bus master devices, the SDRAM controller forms the queue of bus access requests, based amongst other things on a relative priority given to the bus master device which made the request.

SDRAM controller

The present invention provides circuitry and methods for sharing I/O pins between a programmable logic portion and an embedded processor portion of a chip. The circuits in the programmable logic portion and the embedded processor portion can access data signals from and send data signals to the same I/O pins. The data signals are multiplexed to control access to the shared I/O pins. The multiplexers may be controlled by a control signal that determines when particular I/O pins are accessed by the programmable logic portion and the embedded processor portion. Control signals that configure the associated I/O pin circuitry to the correct I/O standard are also multiplexed by the shared I/O circuitry of the present invention. Signals received at the shared I/O pins that are transmitted to the embedded processor portion may be concurrently sent to snoop circuitry within the programmable logic portion.

I/O circuitry shared between processor and programmable logic portions of an integrated circuit

A programmable logic integrated circuit has an embedded processor with a watchdog timer circuit. The watchdog timer circuit is used to detect software or hardware failures. In one implementation, the watchdog timer circuit includes a counter register that advances (e.g., incremented or decremented) with each clock. To prevent the watchdog timer circuit from becoming triggered, the watchdog timer circuit should be reset or reloaded by software. For example, the count register may be reset to a value to start the count over. If the count register is allowed to count to a final or maximum value, the watchdog timer circuit will become triggered, generating a triggered signal that causes the programmable logic integrated circuit to be reset. A reset causes a reloading of the configuration data used to program the programmable logic and embedded processor portions of the integrated data. The configuration data may be stored in an external nonvolatile storage memory.

Embedded processor with watchdog timer for programmable logic

A method and apparatus for configuring a digital system having a programmable logic device and embedded logic from a configuration source that supplies a single serialized configuration bit stream for configuring both the programmable logic device and the embedded logic.

Configuring both a programmable logic device and its embedded logic with a single serialized configuration bit stream

A programmable logic device is reconfigurable between two functionalities, while it is in use. The programmable logic device has a first store, into which configuration data may be downloaded from an external memory device, and a second store, in which a copy of the configuration data is maintained, with the functionality of the programmable logic device being determined by the copy of the configuration data, thereby allowing additional configuration data to be downloaded from the external memory device into the first store, while maintaining the functionality of the device. This allows the device to be used to provide two different functionalities, and to be switched between these two functionalities with minimal delay for reconfiguration of the device.

Updating configuration for programmable logic device

A programmable logic device includes a routing structure, which takes the form of multiple distributed OR gates, which are positioned within the device to allow signals to be input from spaced apart logic elements, and present the input signals to other logic elements, which, again, may be spaced apart throughout the device. Each of the distributed OR gates, and its connections to the other logic elements, acts as a multiplexer. Sufficient of these distributed OR gates are provided to allow a bus structure to be implemented within the device. Since the OR gates are provided separately from the logic elements of the programmable logic device, the required bus structure can be implemented more efficiently.

Distributed bus structure

A programmable logic device is provided with multiple power supplies such that, in one mode of operation, power can be disconnected from at least one part of the programmable logic device, while maintaining power at least to an interface component of the programmable logic device, or to a memory component in which current configuration data are stored, thereby avoiding the need for a configuration sequence when power is reapplied to the whole device. The programmable logic device may be provided as an integrated circuit, having multiple pairs of pins for connection to a supply voltage. Each of the pairs of pins provides power for a different subsection of the programmable logic device.

Programmable logic device

A programmable logic device includes a gate array formed from programmable logic elements, and at least one address decoder structure. The address decoder has a first stage, for receiving bits of an address, and for masking out a first group of least significant bits of said address; a second stage, for comparing a second group of most significant bits of said address with respective comparison bits; and a third stage, for providing an output when all of the bits in said second group of bits of said address match their respective comparison bits. Thus, the address decoder can determine when a received address falls within a range of addresses associated with the address decoder. Multiple address decoders may be provided at spaced apart locations within the gate array, and one address decoder can be associated with each slave device implemented in the gate array. The programmable logic device may be used to implement a bus structure, with a bus master which may be in the form of an embedded processor. One of the multiple address decoders can then be associated with each slave device in the bus structure.

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Roger May