Electric vehicles (EVs) and hybrid vehicles (HEVs) are touted for their energy efficiency and silent operation. The lack of vehicular sound is a safety problem recognized by the U.S. Department of Transportation, which has mandated that these vehicles must be equipped by 2020 to emit sounds at low speeds to alert pedestrians, 
Source: ADIcyclists and others to their presence.
Analog Devices Inc. (ADI) has introduced an embedded system for generating engine sound for EVs and HEVs. The ADSP-BF706 digital signal processor and electric vehicle warning sound system (EVWSS) firmware enables automobile manufacturers in North America and other global regions to comply with future safety regulations mandating external engine sound for EVs and HEVs traveling at low speeds.
The ADI solution includes a complete hardware and firmware reference design. It can be scaled for high performance with the ADSP-BF706 or entry-level applications with the ADAU1450 Digital Audio Processor. The ADSP-BF706 can also be used to create in-cabin engine sound to contribute to an improved driving experience for vehicle owners. The ADSP-BF706 uses memory mapped quad SPI memory, providing faster and simpler access to the stored audio files used to create the engine sound. It can access up to 24 WAV files simultaneously, compared to conventional products that can typically access only five.
ADI’s Sigma Studio Integrated Development Environment (IDE) enables OEMs to graphically tune the audio sound when using the ADAU1450. This allows sound engineers with minimal programming experience to optimize audio performance while reducing development time. A new release of Sigma Studio supporting the ADSP-BF706 is due later this year. In addition, a low-cost CAN software stack runs on the ADSP-BF706 to help customers quickly build automotive-grade prototypes.
ADSP-BF706 product highlights
- Blackfin+ core with up to 400 MHz performance
- Dual 16 bit or single 32 bit MAC support per cycle
- 16 bit complex MAC and many other instruction set enhancements
- Instruction set compatible with previous Blackfin products
- On-chip memory adau1450
- 136KB L1 SRAM with multi-parity-bit protection (64 KB instruction, 64 KB data, 8 KB scratchpad)
- 1 MByte on-chip L2 SRAM with ECC protection
- 512 KByte on-chip L2 ROM
- Key peripherals include
- USB 2.0 HS OTG
- Two CAN2.0B
- ePPI Video I/O
- Two SPORTs (with I2S)
- two quad-SPI/one dual-SPI (with host mode)
- 12C
- Two UART
- SD/SDIO/MMC (4 bit)
