Altera Corporation

Sanjay K Charagulla

Chiakang Sung

Ali H Burney

Khai Nguyen

Joseph Huang

Bonnie I Wang

Yan Chong

Xiaobao Wang

Yu Xu

Leon Zheng

Daniel R Mansur

Jeffrey Tyhach

Techniques are provided for individually adjusting the on-chip termination impedance that is generated by input and output (IO) buffers in an input/output (IO) bank on an integrated circuit. The IO buffers in an IO bank can generate different on-chip termination impedances. And as a result, an IO bank can support more than one class of memory interfaces. An OCT calibration block generates a digital on-chip termination (OCT) calibration code. In some embodiments, circuitry in the IO banks can be configured to shift the OCT calibration code by one or more bits to adjust the series and/or parallel on-chip termination impedance in one or more IO buffers.

Techniques for providing adjustable on-chip termination impedance

Integrated circuits such as programmable logic device integrated circuits with memory interface circuitry are provided. The memory interface circuitry measures the timing characteristics of an associated memory during a series of dummy read operations. A multiplexer and phase detector are used to measure phase shifts of memory group clock signals compared to a system clock signal. The memory interface circuitry uses these measurements to adjust a delay-locked-loop circuit. The delay-locked-loop circuit produces a capture clock that is used to read data from the memory.

Memory interface circuitry with phase detection

Adjustable transceiver circuitry is provided for programmable integrated circuits. The transceiver circuitry has a dynamic phase alignment circuit that can be used for aligning clock and data signals. The transceiver circuitry supports a phase-locked-loop source synchronous mode that can be used to receive data from transmitting integrated circuits that are clocked with a common clock. Each transmitting integrated circuit transmits a clock and associated data signals over a bus. The transceiver circuitry uses a master-slave architecture. A master dynamic phase alignment circuit in each transceiver receives the clock for that bus and selects a corresponding optimal clock phase to use in receiving input data for the bus from a multiphase clock. The master dynamic phase alignment circuit in each transceiver distributes the optimal clock phase to associated slave dynamic phase alignment circuits. Only a single phase-locked loop circuit is need to generate the multiphase clock.

Programmable logic device integrated circuit with dynamic phase alignment capabilities and shared phase-locked-loop circuitry

A system and method for memory control. The system includes a hard-IP memory controller, a soft-IP frequency conversion system, and an interface system. The soft-IP frequency conversion system is coupled to the hard-IP memory controller, and is capable of being programmed to convert data signals between a first frequency and a second frequency.

Fully buffered DIMM system and method with hard-IP memory controller and soft-IP frequency controller

A programmable device I/O architecture allows for a variable number of I/O banks. Each I/O bank is of an I/O bank type. Each I/O bank type has a fixed number of I/O pins. I/O banks of the same I/O bank type are compatible within the same programmable device and between different types of programmable devices. The largest size I/O bank type and intermediate size I/O bank types are adapted to be a compatible supersets of every smaller I/O bank type. Support pins are regularly distributed between data pins in each I/O bank type. Multiple instances of the same or compatible I/O banks are arranged to be accessible from different sides of the programmable device. To facilitate circuit board layout, each I/O bank is arranged as a mirror and/or rotation of other I/O banks on the device.

Modular I/O bank architecture

Circuits, methods, and apparatus for filtering signals at a high-speed data interface. One exemplary embodiment is particularly configured to filter a clock signal at the end of a data burst received by a double-data rate memory interface. A clock input port is either connected or disconnected to an input cell. When a data burst is to be received, the clock input port is connected to the input cell. When the data burst concludes, the clock input port is disconnected from the input cell. In a specific embodiment, a signal is received indicating that a data burst is about to begin and the clock input port is connected to the input cell. The signal later changes state indicating that the last data bit is being received. When the last clock edge corresponding to the last data bit is received, the clock input port is disconnected from the input cell.

DQS postamble filtering

A method and system using a delay-locked loop (DLL) to provide multiple phase locked outputs in discrete phase intervals is disclosed. In one embodiment, a reference clock signal is transmitted through a delay chain having a plurality of delay elements. The delay chain is capable of generating a plurality of output clock signals from the reference clock signal. Each of the output clock signals are delayed in discrete phase shift intervals with respect the delay elements. A first of the output clock signals and the reference clock signal are coupled to a first phase comparator capable of forming a first DLL with the delay chain. A second of the output clock signals and the reference clock signal are coupled to a second phase comparator capable of forming a second DLL with the delay chain. The output clock signal from the first DLL or the second DLL may be programmatically selected.

Enhanced DLL phase output scheme

Methods and apparatus provide PCI Express support on a programmable device. A device includes a hard-coded transceiver that supports functionality associated with the PCI Express physical layer and link layer. The hard-coded transceiver can also support part of the PCI Express transaction layer. Soft-coded logic is used to support higher layer functionality including a portion of the transaction layer to allow custom configuration of PCI Express features such as virtual channels, buffers, prioritization, and quality of service characteristics. The hybrid solution reduces logic resource cost and provides an effective custom configurable solution.

Embedded PCI-Express implementation

Methods and apparatus are provided for providing PCI Express support. A device includes a hard-coded transceiver configured to support protocols such as Fibre Channel and the 10 Gigabit Attachment Unit Interface (XAUI), but the transceiver does not fully support PCI Express. Interface circuitry is configured to supplement or replace hard-coded transceiver components to provide PCI Express support. Interface circuitry allows PCI Express cores to operate with the transceiver that does not fully support PCI Express.

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San Jose, CA, United States of America

Sanjay K Charagulla