AMBE2000

Version 3.0 AMBE-2000™ Vocoder Chip User’s Manual Version 3.0 AMBE-2000™ Vocoder Chip User’s Manual Version 3.0 April, 2000 Copyright ©, 2000 Digital Voice Systems, Inc 234 Littleton Road Westford, MA 01886 This document may not, in whole or in part be copied, photocopied, reproduced, translated, or reduced to any electronic medium or machine readable form without prior consent in writing from Digital Voice Systems, Incorporated. Every effort has been made to ensure the accuracy of this manual. However, Digital Voice Systems, Inc. makes no warranties with respect to the documentation and disclaims any implied warranties of merchantability and fitness for a particular purpose. Digital Voice Systems, Inc. shall not be liable for any errors or for incidental or consequential damages in connection with the furnishing, performance, or use of this manual or the examples herein. This includes business interruption and/or other loss which may arise from the use of this product. The information in this document is subject to change without notice. Trademarks AMBE-2000™ Vocoder Chip is a registered trademark of Digital Voice Systems, Inc. Other product names mentioned may be trademarks or registered trademarks of their respective companies and are the sole property of their respective manufacturers. All Rights Reserved Data subject to change page 2 Visit us at www.dvsinc.com Confidential Proprietary, Subject to Change AMBE-2000™ Vocoder Chip User’s Manual Version 3.0 AMBE-2000™ Vocoder Chip END USER License Agreement 1.0 Preliminary Statements and Definitions 1.1 “END USER” shall mean the person and/or organization to whom the AMBE2000™ Vocoder Chip was delivered or provided to as specified in the purchase order or other documentation. In the event that the END USER transfers his rights under this license to a third party as specified in section 2.2, then this third party shall become an “END USER”. 1.2 Digital Voice Systems, Inc. (DVSI) has developed a voice coding method and algorithm (the “Technology”) based on the Advanced Multi-Band Excitation (“AMBE®”) voice coder. The technology codes speech at bit rates of 2.4 to 9.6 kilobits per second (kbps) including error correction bits. 1.3 "AMBE® Voice Compression Software" shall mean the speech coding software and/or firmware integrated into the AMBE-2000™ Vocoder chip integrated circuit. 1.4 "Voice Codec" shall mean the AMBE-2000™ Vocoder Chip integrated circuit, the AMBE® Voice Compression Software, firmware and associated documentation, including modifications, enhancements and extensions made by or for Digital Voice Systems, Inc. (DVSI) and including circuit diagrams, timing diagrams, logic diagrams, layouts, operating instructions and user manuals. 1.5 DVSI represents that it owns certain “Proprietary Rights” in the Technology and the AMBE® Voice Compression Software, including patent rights in the Technology, and patent rights, copyrights, and trade secrets in the AMBE® Voice Compression Software. 2.0 License Granted 2.1 Subject to the conditions herein and upon initial use of the AMBE-2000™ Vocoder Chip, DVSI hereby grants to END USER a non-exclusive, limited license to use the AMBE® Voice Compression Software in machine readable form solely on the AMBE2000™ Vocoder Chip. Title to the AMBE® Voice Compression Software remains with DVSI. No license is granted for use of the AMBE® Voice Compression Software on other than the AMBE-2000™ Vocoder Chip. No license, right or interest in any trademark, trade name or service mark of DVSI is granted under this Agreement. 2.2 END USER shall not copy, extract, de-compile, reverse engineer or disassemble the AMBE® Voice Compression Software contained in the AMBE-2000™ Vocoder Chip. 3.0 Transfer of License 3.1 The END USER shall have the right to transfer the AMBE-2000™ Vocoder Chip and all rights under this Agreement to a third party by either (i) providing the third party with a copy of this Agreement or (ii) providing the third party with an agreement written by the END USER ( hereinafter “END USER Agreement”) so long as the END USER Agreement is approved in writing by DVSI prior to transfer of the AMBE-2000™ Vocoder Chip. The END USER Agreement shall contain comparable provisions to those contained herein for protecting the Proprietary Information from disclosure by such third party. Third parties shall agree to accept all the terms and conditions under either Agreement or the END USER Agreement. 4.0 Term and Termination 4.1 This Agreement is effective upon initial delivery of the Voice Codec and shall remain in effect until terminated in accordance with this agreement. 4.2 This Agreement shall terminate automatically without notice from DVSI if END USER fails to comply with any of the material terms and conditions herein. END USER may terminate this Agreement at any time upon written notice to DVSI certifying that END USER has complied with the provisions of Section 3.3. 4.3 Upon termination of this Agreement for any reason, END USER shall: (i) return all AMBE-2000™ Vocoder Chip purchased or acquired, or in Licensee’s possession, to DVSI; (ii) have no further rights to any AMBE® Voice Compression Software or the Technology without a separate written license from DVSI; (iii) discontinue all use of the AMBE-2000™ Vocoder Chip; 5.0 Payments 5.1 In consideration of the materials provided as part of the Voice Codec, and in consideration of the license and rights in the AMBE® Voice Compression Software granted by DVSI, and in consideration of DVSI's performance of its obligations hereunder, END USER agrees to pay to DVSI the fee specified in DVSI's invoice. 6.0 Proprietary Notices 6.1 END USER shall not remove any copyright or proprietary notice on the AMBE2000™ Vocoder Chip or on the AMBE® Voice Compression Software. 7.0 Proprietary Information 7.1 The parties agree that the AMBE® Voice Compression Software shall be considered Proprietary Information. 7.2 Except as otherwise provided in this Agreement, END USER shall not use, disclose, make, or have made any copies of the Proprietary Information, in whole or in part, without the prior written consent of DVSI. 8.0 Limited Warranty 8.1 DVSI warrants the Voice Codec to be free from defects in materials and workmanship under normal use for a period of ninety (90) days from the date of delivery. 8.2 Except as stated in Section 7.1, the Voice Codec is provided "as is" without warranty of any kind. DVSI does not warrant, guarantee or make any representations regarding the use, or the results of the use, of the Voice Codec with respect to its correctness, accuracy, reliability, correctness or otherwise. The entire risk as to the results and performance of the Voice Codec is assumed by the END USER. After expiration of the warranty period, END USER, and not DVSI or its employees, assumes the entire cost of any servicing, repair, replacement, or correction of the Voice Codec. 8.3 DVSI represents that, to the best of its knowledge, it has the right to enter into this Agreement and to grant a license to use the AMBE® Voice Compression Software to END USER. 8.4 Except as specifically set forth in this Section 7.0, DVSI makes no express or implied warranties including, without limitation, the warranties of merchantability or fitness for a particular purpose or arising from a course of dealing, usage or trade practice, with respect to the Voice Codec. Some states do not allow the exclusion of implied warranties, so the above exclusion may not apply to END USER. No oral or written information or advice given by DVSI or its employees shall create a warranty or in any way increase the scope of this warranty, and END USER may not rely on any such information or advice. The limited warranties under this section 7.0 give END USER specific legal rights, and END USER may have other rights which vary from state to state. 9.0 Limitation of Liability 9.1 In no event shall DVSI be liable for any special, incidental, indirect or consequential damages resulting from the use or performance of the Voice Codec whether based on an action in contract, tort (including negligence) or otherwise (including, without limitation, damages for loss of business profits, business interruption, and loss of business information), even if DVSI or any DVSI representative has been advised of the possibility of such damages. 9.2 Because some states do not allow the exclusion or limitation of liability for consequential or incidental damages, the above limitations may not apply to END USER. 9.3 DVSI's maximum liability for damages arising under this Agreement shall be limited to 20% (twenty percent) of the fees paid by END USER for the particular Voice Codec which caused the damages or that is the subject matter of, or is directly related to, the cause of action. 10.0 Taxes 10.1 All payments required under Section 4.0 or otherwise under this Agreement are exclusive of taxes and END USER agrees to bear and be responsible for the payment of all such taxes (except for taxes based upon DVSI's income) including, but not limited to, all sales, use, rental receipt, personal property or other taxes which may be levied or assessed in connection with this Agreement. 11.0 Export 11.1 United States export laws and regulations prohibit the exportation of certain products or technical data received from DVSI under this Agreement to certain countries except under a special validated license. As of November 30, 1999 the restricted countries are: Libya, Cuba, North Korea, Iraq, Serbia, Taliban in Afghanistan, Sudan, Burma, Yugoslavia and Iran. The END USER hereby gives its assurance to DVSI that it will not knowingly, unless prior authorization is obtained from the appropriate U.S. export authority, export or re-export, directly or indirectly to any of the restricted countries any products or technical data received from DVSI under this Agreement in violation of said United States Export Laws and Regulations. DVSI neither represents that a license is not required nor that, if required, it will be issued by the U.S. Department of Commerce. Licensee shall assume complete and sole responsibility for obtaining any licenses required for export purposes. 12.0 Governing Law 12.1 This Agreement is made under and shall be governed by and construed in accordance with the laws of the Commonwealth of Massachusetts, except that body of law governing conflicts of law. If any provision of this Agreement shall be held unenforceable by a court of competent jurisdiction, that provision shall be enforced to the maximum extent permissible, and the remaining provisions of this Agreement shall remain in full force and effect. page 3 Visit us at www.dvsinc.com Confidential Proprietary, Subject to Change AMBE-2000™ Vocoder Chip User’s Manual Version 3.0 1. Product Introduction 1.1 1.2 1.3 2 General Information Advantages Typical Applications 6 6 6 7 8 8 8 8 9 9 10 10 10 11 13 14 14 15 16 17 17 17 19 19 19 21 22 24 24 24 25 25 26 26 27 27 27 AMBE™-2000 Application Design Overview 2.1 Basic Operation 2.2 Initial Design Considerations 2.2.1 A/D – D/A Overview 2.2.2 Channel Interface Overview 2.2.3 Speech and FEC Rate Selection Overview 3 Hardware Information 3.1 Special Handling Instructions 3.1.1 Storage 3.2 3.3 Pin Descriptions Clock and Reset Timing 3.4 Crystal / Oscillator Usage 3.4.1 TTL Clock Source 3.4.2 Crystal Oscillator 3.5 3.6 3.7 3.8 4 Package Description Normal Operating Conditions Absolute Maximum Ratings Electrical Characteristics and Requirements Channel Interface 4.1 4.2 Overview Serial Configuration Selection 4.3 Channel Serial Mode 4.3.1 Low Level Timing for Passive and Active Serial Mode 5 Channel Data Format 5.1 Formatted Format 5.2 Formatted Input Format 5.2.1 Formatted Input : Word 0 : Header 5.2.2 Formatted Input : Word 1 : Power Control 5.2.3 Formatted Input : Word 1 : Control Word 1 5.2.4 Formatted Input : Words 2-6 : Rate Info 0, Rate Info 1, Rate Info 2, Rate Info 3, Rate Info 4 5.2.5 Formatted Input : Word 7 : Unused in Input 5.2.6 Formatted Input : Word 8 : Unused in Input 5.2.7 Formatted Input : Word 9 : Unused in Input page 4 Visit us at www.dvsinc.com Confidential Proprietary, Subject to Change AMBE-2000™ Vocoder Chip User’s Manual Version 3.0 5.2.8 5.2.9 5.2.10 Formatted Input : Word 10 :DTMF Control Formatted Input : Word 11 Control Word 2 Formatted Input : Words 12-23 : Channel Data 27 28 29 29 30 30 30 30 30 30 30 32 33 33 33 34 35 35 35 36 36 38 38 38 39 40 40 40 40 41 42 45 45 45 5.3 Formatted Output Format 5.3.1 Formatted Output : Word 0 : Header 5.3.2 Formatted Output : Word 1 : ID (Power Control) 5.3.3 Formatted Output : Word 1 :Control Word 1 This 8-bit control word indicates the activity of various functions. 5.3.4 Formatted Output : Words 2-6 : Rate Info 0, Rate Info 1, Rate Info 2, Rate Info 3, Rate Info 4. 5.3.5 Formatted Output: Word 7 : Bit Error Rate 5.3.6 Formatted Output : Word 10 : DTMF Control 5.3.7 Formatted Output : Word 11 :Control Word 2 5.3.8 Formatted Output : Words 12-23 :Channel Data 5.4 Unformatted Serial Format 5.4.1 Unformatted Serial Output Format 5.4.2 Unformatted Serial Input Format 6 A/D-D-A Interface 6.1 6.2 A/D-D/A Overview Configuring the A/D-D/A Interface using CODEC_SEL[1-0] 6.3 Low Level A/D–D/A Timing Low Level Timing for A/D-D/A in Active and Passive Modes 7 Special Functions 7.1 7.2 7.3 7.4 7.5 Hardware vs. Software Selection Note Coding Rate Selection Echo Cancellation Voice Activation Detection (VAD), Comfort Noise Insertion (CNI) Dual Tone Multiple Frequency, Detection and Generation 7.6 Normal Power and Power Saving Modes 7.6.1 Standard Sleep Mode 7.6.2 Power Down 7.7 8 Slip Enable Appendices 8.1 Example A/D-D/A Usage 8.1.1 AD73311 page 5 Visit us at www.dvsinc.com Confidential Proprietary, Subject to Change AMBE-2000™ Vocoder Chip User’s Manual Version 3.0 1. Product Introduction 1.1 General Information Digital Voice Systems Inc.’s AMBE-2000™ Vocoder Chip is an extremely flexible, high-performance, single chip, speech compression coder. It provides superior voice quality at low data rates. It provides a real-time, full-duplex implementation of the standard-setting AMBE® voice compression software algorithm. DVSI’s patented AMBE® voice compression technology has been proven to outperform CELP, RELP, VSELP, MELP, ECELP, MP-MLQ, LPC-10, and other competitive technologies. Numerous evaluations have shown its ability to provide performance equal to today’s digital cellular systems at under half the data rate. The AMBE® voice compression algorithm is used in applications throughout the world, including the next generation of digital mobile communication systems. The AMBE-2000™ Vocoder chip provides a high degree of flexibility in selecting the speech and FEC (Forward Error Correction) data rates. The user can separately select these parameters in 50 bps increments for total rates from 2.4 kbps to 9.6 kbps. Typically for higher error rate channels, the user will apportion a greater percentage of the total bit rate to FEC coding. The AMBE-2000™ voice coder maintains natural voice quality and speech intelligibility at rates as low as 2.4 kbits/sec. The AMBE® algorithm’s low complexity allows it to be fully integrated into a low cost, low power integrated circuit, the AMBE2000™ Vocoder Chip. The AMBE-2000™ Vocoder Chip offers similar features as to DVSI’s AMBE-1000™ Vocoder Chip allowing it to be incorporated into systems already design for the AMBE-1000™ and is interoperable with other DVSI products. The AMBE2000™ Vocoder Chip delivers improved performance and enhanced modes such as 4.0 kbps toll quality speech and convolutional FEC coding. Along with these enhancements the AMBE-2000™ Vocoder Chip employs a control interface along with the variable data rates and FEC selection as found in . 1.2 Advantages • • • • • • • • Superior Voice Quality Low Cost No External Memory Required Robust to Bit Errors & Background Noise Variable Data Rates - 2.0 kbps to 9.6 kbps Variable FEC Rates - 50 bps to 7.2 kbps Very Low Power (65mW @ 3.3V, 0.11mW Deep Sleep) Compact Single Chip Solution: 100 pin TQFP High Quality Low Data Rate Speech Coding DVSI’s Full Duplex AMBE® Voice Coder Supports Data Rates of 2.0 kbps to 9.6 kbps in 50 bps increments User Selectable Forward Error Correction rates Viterbi Decoder (rate 1/4 or more) 16 Level Soft Decision Decoding Voice Activity Detection (VAD) / Comfort Noise Insertion 16 ms. Echo Cancellation Single and Dual Tone (DTMF) Detection and Generation page 6 Visit us at www.dvsinc.com Confidential Proprietary, Subject to Change Features • • • • • • • • • AMBE-2000™ Vocoder Chip User’s Manual Version 3.0 • • • Power-Down Mode Minimal algorithmic processing delay DTMF detection and regeneration with North American call progress tones 1.3 Typical Applications • • • • • • • Satellite Communications Digital Mobile Radio Secure Communications Cellular Telephony and PCS Voice Multiplexing Voice Mail Multimedia Applications page 7 Visit us at www.dvsinc.com Confidential Proprietary, Subject to Change AMBE-2000™ Vocoder Chip User’s Manual Version 3.0 2 AMBE™-2000 Application Design Overview 2.1 Basic Operation In its simplest model, the AMBE-2000™ can be viewed as two separate components, the Encoder and the Decoder. The Encoder receives an 8kHz. sampled stream of speech data (16-bit linear, 8-bit Alaw, or 8-bit ulaw) and outputs a stream of channel data at the desired rate. Conversely the Decoder receives a stream of channel data and synthesizes a stream of speech data. The timing for the interfaces for the AMBE-2000™ Encoder and Decoder are fully asynchronous. Figure 2-A Basic Operation AMBE-2000 8kHz Speech Data AMBE-2000 Compressed Data @ 2400-9600bps Encoder Decoder 8kHz Speech Data 8kHz Speech Data Decoder Compressed Data @ 2400-9600bps Encoder 8kHz Speech Data Typically the speech interface is an external A/D-D/A chip. The format of the incoming and outgoing speech data streams are coupled, that is to say they must be the same format (16-bit linear, 8-bit Alaw, or 8-bit µlaw). The channel interface is commonly (but not limited to) an 8 or 16 bit microprocessor or other suitable ‘glue logic’ hardware capable of performing the rudimentary formatting functions between the AMBE-2000™ channel format and the format of the system channel under design. Optional functions of the chip, such as echo cancellation, voice activation/detection, power mode control, data/FEC rate selection, etc. are controlled either through hardware control pins (see Section 0) and/or through the decoder command interface (see Section 4) Data sent into the decoder for function control purposes is distinguished from the data to be decoded into speech through a channel format which is described in Section 4. 2.2 Initial Design Considerations • • • Some of the initial design considerations the application engineer will face are the following: Choice of A/D-D/A chip. Choice of Channel Interface. Speech and FEC Rates. 2.2.1 A/D – D/A Overview The choice of the A/D-D/A chip is critical to designing a system with superior voice quality. Given that Alaw and µlaw companding chips are already incorporating some compression to reduce the number of bits per sample, it is recommended that, when possible, a 16-bit linear device be used for maximum voice quality. When choosing a device, pay particular attention to Signal to Noise ratios and Frequency Responses of any filters that may be present on the analog front end of these chips. The Alaw and µlaw interfaces are also provided for the design engineer who is trying to fit to pre-existing conditions or is under other cost type restraints. page 8 Visit us at www.dvsinc.com Confidential Proprietary, Subject to Change AMBE-2000™ Vocoder Chip User’s Manual Version 3.0 2.2.2 Channel Interface Overview The channel interface is meant to be flexible to allow for easy integration with the system under design. The basic hardware unit of the interface is a serial port. The serial mode can run in passive or active modes. Simply stated, the control signal for serial mode can be derived by the AMBE-2000™ chip or they can be derived externally. Under normal operation, every 20msec the encoder outputs a frame of coded bits, and the decoder needs to be delivered a frame of coded bits. There is some formatting of the data for both the encoder and the decoder. The primary purpose of the formatting is to provide alignment information for the encoded bit stream. The data has two formats, Formatted and Unformatted. Serial mode can run in either Formatted or Unformatted mode. The Formatted and Unformatted modes are explained in full detail in Section 4, but essentially the two formats are trying to achieve the same function, to provide positional information regarding the outgoing and incoming coded data streams. In Formatted mode each 20msecs of output data from the encoder is preceded by a known structure. This structure also embeds some status type flags, meant for local control purposes, within it. The only data from the Formatted format that is typically sent across the transmission channel under design are the actual encoded bits at the desired rate. In Formatted mode, it is the responsibility of the designed system to pass enough information along with the encoded bits such that the Formatted format needed by the decoder can be reconstructed on the other side. This extra information, or overhead, is going to be very specific to the system under design, but at a minimum needs to pass enough information to reliably reconstruct the 20msec frame structure at the other end for the decoder. In Unformatted mode the data coming out of the encoder can be thought of as a continuous stream of voice data with the framing information embedded within the encoded bits. One advantage of this type of set-up is that the system does not have to add any bandwidth for overhead to the channel. The disadvantage is that the decoder needs 10-12 incoming frames in order to gain synchronization with the data stream before it can properly synthesize the speech waveform. Also, the Unformatted mode only commits a single bit per frame to maintaining data alignment. In higher error rate channels the performance will be improved by adding more bits per frame to the alignment information (which is more easily performed when using Formatted mode) Additional flexibility is given to the channel interface to the encoder and decoder by allowing the AMBE-2000™ Vocoder Chip to run in Passive or Active modes. In Passive mode, data strobes are provided by an external source, while in Active mode, data strobes are provided by the AMBE-2000™ Vocoder Chip. The serial interfaces can be run in Passive or Active modes. See Section 4 for full details and timing for both Formatted and Unformatted data. 2.2.3 Speech and FEC Rate Selection Overview The total coded bit rate is the sum of two components, the Speech Data and the Forward Error Correction (FEC) Data. The addition of FEC data to the speech data allows the decoder to be able to correct a limited amount of errors within each frame should they arrive corrupted. If the channel is expected to have more errors then more bits should be dedicated to FEC. At the same time, voice quality will increase if the number of speech bits can be maximized. page 9 Visit us at www.dvsinc.com Confidential Proprietary, Subject to Change AMBE-2000™ Vocoder Chip User’s Manual Version 3.0 3 Hardware Information 3.1 Special Handling Instructions The AMBE-2000 uses the TM320-LC541-66 core. For more details on handeling, electrical characteristics, packaging, or timing constraints please refer to the TMS320-C54x manual found at http://www-s.ti.com/sc/psheets/sprs039c/sprs039c.pdf (Adobe Acrobat). Although the AMBE-2000™ Vocoder Chip incorporates input protection circuitry, to avoid damage from the accumulation of a static charge, industry standard electrostatic discharge precautions and procedures must be employed during handling and mounting. The 100 pin TQFP package design of the AMBE-2000™ Vocoder Chip allows it to be mounted by infrared reflow, vaporphase reflow or equivalent processes. The peak package body temperature must not exceed 220°C. The AMBE-2000™ Vocoder Chip requires baking before mounting, if any of the following conditions exist: • • • • Humidity indicator card (included in packaging) shows exposure to > 20 % when read at 23°C + 5°C Devices were not shipped in a package designated as “moisture controlled.” Not mounted within 168 hours of receipt, at factory conditions of