CSR

BlueTunes® ROM

For Headsets and Speakers

BlueTunes ROM | CSR

Description

BlueTunes ROM addresses the growing market for stereo wireless multimedia functionality as the world’s first ROM-based Bluetooth® solution with an integrated DSP. BlueTunes allows end-users to switch seamlessly between wireless music playback and voice calls, providing an enjoyable user-experience. BlueTunes ROM is a low-power and cost-effective, high-quality Bluetooth music solution for stereo headset and wireless speaker products.

Key features

  • Support for A2DP 1.2, AVRCP 1.0, HSP 1.0 and HFP 1.5 Bluetooth profiles including 3-way calling
  • FastStream (low latency CODEC) for video and gaming applications
  • SBC and MP3* decoding CVC echo and noise reduction algorithm
  • Very low power consumption
  • Superior audio quality
  • High performance RF (receive sensitivity -90 dBm, transmit power +8dBm)
  • Green (RoHS compliant and no antimony or halogenated flame retardants)

Benefits

BlueTunes ROM is based on CSR's highly integrated BlueCore5-Multimedia device. This incorporates a 24-bit Kalimba DSP core with a RISC processor, stereo CODEC, Bluetooth v2.1 + EDR radio and integrated battery charger.

FastStream wireless links

  • Stereo streamed over a Bluetooth link normally has a latency of around 200 msec. With CSR's proprietary FastStream technology this can be reduced to just 28-34 ms
  • Originally developed to meet the demanding needs of wireless peripherals in gaming applications, FastStream effectively eliminates 'lip synchronisation' issues and similar problems, providing a platform to create highly versatile headphones

Support for SBC and MP3 CODECs

  • Supports the mandatory Bluetooth compression coding/decoding scheme - Sub Band Coding or SBC (which is license-free)
  • CSR also offers optional support for the widely used MP3* CODEC (MPEG 1 and 2 sample rates, constant and variable bit rates). This format can provide improved audio quality and reduce power consumption
  • By allowing the source to use the native music storage format such as MP3, developers can eliminate processor-intensive 'transcoding' (decompression/recompression) operations before transmission

Alternative CODEC formats

  • MP3 and SBC formats are supported by the standard BlueTunes ROM design, but CSR also has other transcoding routines available for the Kalimba DSP core that can be used to support custom application developments

Excellent power economy

  • Offers exceptional power economy thanks to its very high level of integration, combined with highly optimised power saving strategies
  • Excellent talk times with CVC echo and noise cancellation

Interoperability-tested solution

  • CSR subjects new example designs to a rigorous testing program to ensure interoperability
  • At CSR's purpose-built interoperability laboratory, the BlueTunes ROM design has been tested against well over 50 of the most popular GSM/3G handsets, including CDMA products with A2DP enabled links for streaming music over Bluetooth.

Product details

Radio

  • Common TX/RX terminal simplifies external matching; eliminates external antenna switch
  • BIST minimises production test time
  • Bluetooth v2.1+EDR specification compliant

Transmitter

  • 7dBm RF transmit power with level control from on-chip 6-bit DAC over a dynamic range >30dB
  • Class 2 and Class 3 support without the need for an external power amplifier or TX/RX switch

Receiver

  • -90dBm receive sensitivity
  • Integrated channel filters
  • Digital demodulator for improved sensitivity and co-channel rejection
  • Real time digitised RSSI available on HCI interface
  • Fast AGC for enhanced dynamic range

Synthesiser

  • Fully integrated synthesiser requires no external VCO, varactor diode, resonator or loop filter
  • Compatible with crystals between 8 and 32MHz (in multiples of 250kHz) or an external clock

Physical Interfaces

  • SPI for system debugging
  • I²C compatible interface to external EEPROM containing device configuration data (PS Key)
  • UART interface
  • 2 LED drivers with faders

Auxiliary Features

  • Crystal oscillator with built-in digital trimming
  • Power management includes digital shutdown and wake-up commands with an integrated low-power oscillator for ultra-low power Park/Sniff/Hold mode
  • Clock request output to control external clock
  • 2 integrated linear regulators: 1.5V output from 1.7V to 1.95V input
  • Integrated high-efficiency switch-mode regulator: 1.8V output from 2.5V to 4.4V input
  • Power-on-reset cell detects low-supply voltage
  • Integrated charger for lithium ion/polymer batteries

Kalimba DSP

  • Very low power Kalimba DSP coprocessor, 64MIPS, 24-bit fixed point core
  • Support for SBC and MP3* CODEC for improved audio quality
  • Single cycle MAC; 24 x 24-bit multiply and 56-bit accumulator
  • 32-bit instruction word, dual 24-bit data memory
  • 6K x 32-bit program RAM, 8K x 24-bit + 8K x 24-bit data RAM
  • 64 x 32-bit program memory cache when executing from ROM

Stereo audio CODEC

  • 16-bit internal stereo CODEC
  • DAC for stereo audio
  • ADC dual channel mono voice band audio
  • Integrated amplifiers for driving 16Ω speakers; no need for external components
  • Support for single-ended speaker termination and line output
  • Integrated low-noise microphone bias

Baseband and Software

  • Internal ROM
  • 48KB of internal RAM, allows full-speed data transfer, mixed voice/data and full piconet support
  • Logic for FEC, HEC, access code correlation, CRC, demodulation, encryption bit stream generation, whitening and transmit pulse shaping
  • Transcoders for A-law, μ-law and linear voice from host and A-law, μ-law and CVSD voice over air
  • FastStream, CSR low latency CODEC significantly reduces the latency of the audio link, from source to sink, avoiding lip-sync issues when simultaneously listening to audio and watching video images
  • Configurable stereo headset ROM software to setup headset features and user interface
  • HFP 1.5 (including 3-way calling) and HSP 1.0 support
  • Bluetooth v2.1 + EDR specification secure simple pairing support
  • BlueTunes ROM QFN supports a high-performance DSP based CVC 2-mic noise reduction and echo cancellation
  • BlueTunes ROM QFN also supports a DSP based 1-mic CVC noise reduction and echo cancellation

Package options

  • QFN 68-lead, 8 x 8 x 0.9mm, 0.4mm pitch

* MP3 support requires an appropriate license from Thomson.

 

Subject to approval, a datasheet can be made available for this product via CSR Support.

  • © 2012 CSR plc. All rights reserved | Bluetooth® is a trademark owned by the Bluetooth SIG., Inc.
  •  
  • CSR plc is a company registered in England and Wales. Registered office: Churchill House, Cambridge Business Park, Cowley Road, Cambridge, CB4 0WZ
  • Registered Number: 04187346 | VAT number (GB787433096)