Altera Corporation

Benjamin J Esposito

Asher Hazanchuk

Hong Shan Neoh

Robert L Pelt

Suleyman Sirri Demirsoy

Lawrence Rigby

David J Moore

Christopher Cook

An integrated circuit may have specialized processing blocks that are configurable to operate as arithmetic operators that may implement amongst others multiplication, addition, sum-of-product, and multiply-accumulation operations in a first mode. In a second mode, the specialized processing blocks may operate as multiplexers and several specialized processing blocks may be cascaded to implement wider multiplexing functions. In a third mode, the specialized processing blocks may operate as register pipelines.

Programmable integrated circuits with multiplexer and register pipelining circuitry

A method for performing multiplication on a field programmable gate array includes generating a product by multiplying a first plurality of bits from a first number and a first plurality of bits from a second number. A stored value designated as a product of a second plurality of bits from the first number and a second plurality of bits from the second number is retrieved. The product is scaled with respect to a position of the first plurality of bits from the first number and a position of the first plurality of bits from the second number. The stored value is scaled with respect to a position of the second plurality of bits from the second number and a position of the second plurality of bits from the second number. The scaled product and the scaled stored value are summed.

Method and apparatus for implementing a multiplier utilizing digital signal processor block memory extension

A programmable integrated circuit device such as a programmable logic device can be configured as a finite impulse response (FIR) filter capable of operating in decimation mode. The device includes at least one user-configurable random access memory block, and that user-configurable random access memory is configured as coefficient memories and data sample memories. The memories are large enough to hold up to all of the coefficients of the filter and a plurality of data samples at one time. Because the data samples and coefficients need not be shifted through the filter at the programmable logic device clock rate, overclocking of the filter is not necessary. The filter can run at a clock rate which is the same as the input data rate, while taking advantage of the available random access memory to mimic a shift register.

Implementation of decimation filter in integrated circuit device using ram-based data storage

Techniques and an apparatus for producing pulse width modulation (PWM) edges are described. A PWM controller circuit with a polyphase counter is described. The polyphase counter may comprise a plurality of counters. Each of the counters may be set to a specific initial count value. A polyphase decoder block with a plurality of sets of high/low decoders are coupled to outputs from the polyphase counter. A set/reset block with a plurality of set/reset logic elements is coupled to outputs from the polyphase decoder block. A serializer is coupled to outputs from the plurality of set/reset blocks to generate PWM edges. Multiple parallel phases of a PWM pulse may be created with the circuit. Using a polyphase counter and comparator to create multiple parallel phases may speed up the controller circuit and provide a finer tuning resolution.

Fine tuned pulse width modulation

A sample rate converter in which filtering is decomposed into phases as permitted by zero padding is described. The outputs of the phases are issued in the correct sequence to provide the resampled sequence.

Sample rate conversion by controlled selection of filter outputs

Methods, circuits, and an apparatus for filtering high-speed serial data is disclosed. In one embodiment, a Programmable Logic Device (PLD) is configured with a filter circuit for filtering serial data at a first clock rate. The filter circuit converts an N number of serial data streams into an N number of M-bit words based on a deserialization factor. The M-bit words are converted to an M number of N-bit data words. The N-Bit data words are filtered at a second clock rate, reformatted, serialized, and outputted as individual serial data streams at the first clock rate. In one embodiment, the N-bit data words are digitally filtered by a Finite Impulse Response (FIR) filter operating at the second clock rate. The data output of the FIR filter is then serialized into an N number of serial data output streams operating at the first clock rate.

High-speed FIR filters in FPGAs

Efficiently implemented multi-channel integrators and multi-channel differentiators utilize a delay section in a single integrator or differentiator in lieu of parallel integrator or differentiator lines to handle multi-channel data flow and processing. The delay section functions like a shift register, greatly reducing the space and/or resources required for implementing the integrator or differentiator. Such integrators and differentiators can be used in multi-channel decimators, interpolators and numerically controlled oscillators in place of multiple instances of single channel integrators that have had to be used in earlier systems. These structures and devices can be implemented in programmable devices such as PLDs and similar devices, in which the delay section can be implemented in embedded memory in the device. Multi-stage decimators and interpolators can use multiple instances of an integrator and/or differentiator in series.

Efficient implementation of multi-channel integrators and differentiators in a programmable device

A clock synthesis circuit includes a polyphase numerically controlled oscillator, an extraction circuit, and a clock signal generation circuit. The polyphase numerically controlled oscillator generates sets of periodic output signals. Each set of the periodic output signals represents a different phase of a periodic waveform signal. The extraction circuit extracts a most significant bit from each set of the periodic output signals of the polyphase numerically controlled oscillator to generate most significant bits. The clock signal generation circuit converts the most significant bits into a serial bit stream that serves as an output clock signal.

Clock synthesis using polyphase numerically controlled oscillator

A multichannel numerically controlled oscillator is provided. The multichannel numerically controlled oscillator has a dual port memory. An output function generation lookup table in the dual port memory is used to generate output functions for the numerically controlled oscillator. A first channel of output is generated based on a first address signal that is presented on a first port of the dual port memory. A second channel of output is generated based on a second address signal that is presented on a second port of the dual port memory. First and second phase accumulators may be used to produce the address signals for the first and second ports of the dual port memory, respectively. The phase accumulators may each contain a register, an adder, and a feedback path. The registers in the phase accumulators and the dual port memory may handle signals at the clock rate of the output channels.

Multichannel memory-based numerically controlled oscillators

Improved error correction techniques and circuitry are provided. The error correction circuitry may be integrated with a programmable logic device (PLD), or it may be wholly or partly on a separate integrated circuit. The circuitry may be capable of providing data recovery during extended drop out periods of a high speed serial link with an embedded clock signal.

Maintaining data integrity for extended drop outs across high-speed serial links

A programmable logic device includes at least one RAM block generating a first multi-bit calculation result which may, but does not necessarily, involve a multiplication of two operands. A shift operation is driven by a second multi-bit calculation result shifts the second multi-bit calculation result by at least one bit to generate a shifted second multi-bit calculation result. A multi-bit adder coupled to the at least one RAM block adds the shifted second multi-bit calculation result to the first multi-bit calculation result.

Variable fixed multipliers using memory blocks

A user logic design to hardware application is provided that efficiently implements in a PLD a user logic design multiplier using both programmable logic circuitry and one or more multipliers embedded in DSP circuitry integrated in the PLD. A smaller DSP multiplier may be used by implementing the user logic design multiplier in a sum of partial product arrangement in which one of the partial products is generated using the smaller DSP multiplier with the remaining partial products being generated by multipliers implemented using programmable logic circuitry.

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Ovideo, FL, United States of America

Benjamin J Esposito