                    Core name: Xilinx LogiCORE DDS Compiler
                    Version: 4.0
                    Release Date: January 11 2012

    ================================================================================

    This document contains the following sections:

    1. Introduction
    2. New Features
    3. Supported Devices
    4. Resolved Issues
    5. Known Issues
    6. Technical Support
    7. Other Information
    8. Core Release History
    9. Legal Disclaimer

    ================================================================================

    1. INTRODUCTION

    For installation instructions for this release, please go to:

       www.xilinx.com/ipcenter/coregen/ip_update_install_instructions.htm

    For system requirements:

       www.xilinx.com/ipcenter/coregen/ip_update_system_requirements.htm

    This file contains release notes for the Xilinx LogiCORE IP DDS Compiler v4.0
    solution. For the latest core updates, see the product page at:

       www.xilinx.com/products/ipcenter/DDS_Compiler.htm

    2. NEW FEATURES

    - ISE 13.4 software support
    - ISE 13.3 software support
    - ISE 13.2 software support
    - Support for Artix-7 with ISE 13.2
    - ISE 13.1 software support, Virtex-7 and Kintex-7 support
    - ISE 12.1 software support
    - Support for Virtex-6Q and Spartan-6Q with ISE 12.1
    - ISE 11.4 software support
    - Support for Automotive Spartan-6 with ISE 11.4
    - Support for Spartan-6 Low Power with ISE 11.4
    - Support for Virtex-6 Low Power and Virtex-5Q with ISE 11.3

    - Option added to use core as Phase Generator or SIN/COS Lookup Table only.
      This capability can allow users to custom build a Direct Digital
      Synthesizer (DDS) to fit individual application needs.

    - Increased Spurious Free Dynamic Range (SFDR) from 120dBs to 150dBs.

    - Option to configure DDS using system-level parameters (SFDR and Frequency
      Resolution) or hardware parameters (Phase and Output Width).

    - Option to configure phase increment and phase offset as constant,
      programmable or dynamic (for modulation).

    - SFDR range with no noise shaping increased to 150dBs for low frequency
      resolution (that is, when Phase Width <= 16-bits. Note that Phase Width
      was referred to as Accumulator Width in previous versions).

    - Taylor Series Corrected can now be used for lower SFDR (that is >66dBs)
      offering solutions which trade reduced Block RAM resources for increased
      XtremeDSP slices. (Previously Taylor Series Corrected could only be used
      for SFDR above 90dBs).

    - Taylor Series Corrected has been enhanced to avoid the potential SFDR
      limits described in previous datasheets (see Known Issues section for
      further details).

    - Phase width has been reduced in multi-channel DDS to give reduced
      resources whilst maintaining frequency resolution. The update from
      previous versions automatically increases frequency resolution to
      maintain the same phase width as a previous versions.

    - PHASE_OUT now optional.

    - Supports automatic core update from DDS Compiler v3.0, v2.1 and v2.0.

    Note: This core supersedes DDS Compiler v3.0. DDS Compiler version 4.0
    is not bit-accurate with respect to earlier versions. In particular,
    first order Taylor Series Correction table entries have been optimized
    to improve overall accuracy. Extended range of DDS with no noise shaping
    may reduce DATA width requirements. The update function will aim to adjust
    Frequency Resolution to maintain the phase width and associated DATA width.
    Note that this may result in the specified Frequency Resolution parameter
    changing. However, as phase width is maintained, this will not affect
    the actual resolution of frequency or phase values. Also, there have been
    changes to latency, in particular to accommodate the new dynamic phase
    increment and phase offset options. Accumulator Latency has been removed
    and is assumed to be One.

    3. SUPPORTED DEVICES

    The following device families are supported by the core for this release.

    Zynq-7000*

    Virtex-7 XC XT/HT/T
    Virtex-7 -2L XC XT/T

    Virtex-6 XC CXT/LXT/SXT/HXT
    Virtex-6 XQ LXT/SXT
    Virtex-6 -1L XQ LXT/SXT
    Virtex-6 -1L XC LXT/SXT

    Kintex-7 XC
    Kintex-7 -2L XC

    Artix-7 XC

    Spartan-6 XC LX/LXT
    Spartan-6 XA
    Spartan-6 XQ LX/LXT
    Spartan-6 -1L XQ LX
    Spartan-6 -1L XC LX

    Virtex-5 XC LX/LXT/SXT/TXT/FXT
    Virtex-5 XQ LX/ LXT/SXT/FXT

    Virtex-4 XC LX/SX/FX
    Virtex-4 XQ LX/SX/FX
    Virtex-4 XQR LX/SX/FX

    Spartan-3 XC
    Spartan-3 XA
    Spartan-3A XC 3A / 3A DSP / 3AN
    Spartan-3A XA 3A / 3A DSP
    Spartan-3E XC
    Spartan-3E XA

    *To access these devices in the ISE Design Suite, contact your Xilinx FAE.

    4. RESOLVED ISSUES

      - For integer SFDR values the Phase Angle Width may be up to 1-bit
        smaller than intended resulting in reduced SFDR by upto 6 dBs.
        - CR529605
        - AR33261

      - For some latency values multi-channel phase offset channel out by one.
        - CR457411
        - AR 30325

      - Address bus (ADDR) not registered with DATA and REG_SELECT and WE, so one
        cycle out.
        - CR529789
        - AR33263

      - SIN/COS look-up table in DDS sometimes mapped to Block ROM when Memory Type
        was specified as Distributed ROM.
        - CR529791
        - AR33264

      - Behaviour when a programmable phase increment is written through the
        register interface.
        - CR492997
        - Section added to datasheet, entitled Core Timing, to better explain
          the latency of register writes.

      - Latency reported by GUI when Latency Configuration is Auto may be inconsitent
        with that of the core.
        - CR529794

    5. KNOWN ISSUES

    The following are known issues for v4.0 of this core at time of release:

       - Increase in registers for single channel Speed optimized DDS using
         XtremeDSP slices.
           - CR529793
           - AR33265
           - For a single channel DDS configured with Maximal DSP Use,
             programmable phase increment and Speed as the Optimization
             Goal there will be a small increase in the number of registers
             used by the core. This results from a change made in version 4.0
             to improve the consistency with which the phase increment and
             offset are absorbed into the XtremeDSP slice. Previously, phase
             increment register was absorbed into the XtremeDSP slice when
             Optimization Goal was either Area and Speed, whilst phase offset
             was only absorbed when Optimization Goal was Area. When this
             happens the initial value is set to zero. In v4.0
             absorption of both phase increment and offset only occurs when
             the Optimization Goal is Area. Speed optimization can be selected
             to avoid absorption and so enable a non-zero initial value. Also,
             in v4.0 the GUI enforces an zero initial value when a register is
             absorbed. The impact of this change is considered minimal as it
             will not happen on cores that are optimized for area.

       - Number of 18k BRAMs increased from 1 to 2 for 102 < SFDR <= 120dBs
           - Previous versions of the DDS Compiler restricted RAM usage in
             the range 102 < SFDR <= 120dBs to 1 BRAM, and provided a
             warning in the datasheet to ensure that care was taken not to
             use frequencies that could result in reduced SFDR. To provide a
             more robust solution, this restriction has been removed. The new
             solution will use one extra 18k BRAM in this range of SFDR. In
             addition, fabric has been reduced through the use of an extra
             XtremeDSP slice. Should either of these enhancements are not
             appropriate, then it is recommended that version 3.0 be used.
             Alternatively, it may also be possible to use v4.0 with an SFDR
             target of 102dBs and Taylor Series Correction, as internal
             corrections are performed to a higher precision and may provide
             higher SFDR with similar frequency restrictions (that is, phase
             increments should not be chosen that just toggle the top 18-bits
             of the phase accumulator).

    The most recent information, including known issues, workarounds, and
    resolutions for this version is provided in the IP Release Notes Guide
    located at

       www.xilinx.com/support/documentation/user_guides/xtp025.pdf

    6. TECHNICAL SUPPORT

    To obtain technical support, create a WebCase at www.xilinx.com/support.
    Questions are routed to a team with expertise using this product.

    Xilinx provides technical support for use of this product when used
    according to the guidelines described in the core documentation, and
    cannot guarantee timing, functionality, or support of this product for
    designs that do not follow specified guidelines.

    7. OTHER INFORMATION

    - None

    8. CORE RELEASE HISTORY

    Date        By            Version      Description
    ================================================================================
    01/11/2012  Xilinx, Inc.  4.0          ISE 13.4 support
    10/19/2011  Xilinx, Inc.  4.0          ISE 13.3 support
    06/22/2011  Xilinx, Inc.  4.0          ISE 13.2 support, Artix-7 support
    03/01/2011  Xilinx, Inc   4.0          ISE 13.1 support, Virtex-7 and Kintex-7 support
    10/29/2010  Xilinx, Inc.  4.0          ISE 7 Series Monthly Snapshot - (O.28)
    04/19/2010  Xilinx, Inc.  4.0          ISE 12.1, Virtex-6Q and Spartan-6Q support
    12/02/2009  Xilinx, Inc.  4.0          Spartan-6 Lower Power device support and Automotive Spartan-6 support
    09/16/2009  Xilinx, Inc.  4.0          Virtex-6 Lower Power device support
    06/24/2009  Xilinx, Inc.  3.0          Virtex-6, Spartan-6 support
    03/24/2008  Xilinx, Inc.  2.1          Bugfixes
    05/17/2007  Xilinx, Inc.  2.0          Virtex-5 and Spartan-3ADSP support
    11/30/2006  Xilinx, Inc.  1.1          Bugfixes
    09/28/2006  Xilinx, Inc.  1.0          Initial release
    ================================================================================

    9. LEGAL DISCLAIMER

    (c) Copyright 2006 - 2011 Xilinx, Inc. All rights reserved.

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