Analog aims DSPs at embedded control tasks

EDN Europe, 25 Jan 2010

Analog Devices has introduced a new series of Blackfin DSPs, numbered BF50x, under the slogan of “making embedded signal processing easy”: it intends the new parts for industrial applications such as motor and power control. They are 400-MHz parts that come with 12-bit SAR analogue-to-digital converters, and with up to 4 Mbytes of flash memory. To reduce the cost of entry to begin development with the chips, ADI has added a basic development kit at $199, and a JTAG-based emulator at $150.
According to ADI’s Anders Frederiksen, marketing manager for motor control, the new chips represent the latest steps in a continuing process matching the features of DSP chips to the needs of specific market segments; as well as motor control he alludes to developing product areas such as smart metering.
In fact, and to give the sector the full 12-bit ADC precision that it demands, along with the flash memory – a technology that ADI does not develop in-house – the new Blackfins are not monolithic chips but multi-chip modules that match ADI’s DSP core, and one of its ADCs, with the memory die. Costs are, Frederiksen says, “close to” monolithic levels.
Frederiksen says that to broaden the market appeal of the DSPs, the BF50x familyand its support tools focus on ease-of use and ADI has priced them at a level between a conventional mid-range microcontroller, and a low-end “classical” DSP – in the range $4.50 to $10.60 in volume. The BF504 does not have the flash memory, and is the $4.50-price-point device; the 504F adds the flash memory for $6.50; the higher-performing 506F (with the flash) represents the upper end of the price range.
The ADC delivers 11.5 effective number of bits (ENOB), for use in power inverters, uninterruptible power supplies (UPS), servo controls and motor controls. The chips are also low power, in both active and standby states; at 400 MHz the are in the 0.25-W region. The Blackfin BF50x series also introduces a new peripheral to the Blackfin portfolio - the ADC Control Module (ACM) - which provides a low-overhead, precise means to synchronize ADC sampling with external events. Why would you use the Blackfin rather than an MCU? Frederiksen cites applications that demand a combination of real-time performance and precision, where improved accuracy yields results in areas such as efficient control of power.
The series, ADI asserts, delivers approximately twice the DSP processing power compared other similarly-priced processors. Under the Berkeley Design Technology (BDTI) DSP Kernel Benchmark, the BF504 obtained a BDTIsimMark2000/$ score of 498, based on a BDTIsimMark2000 of 2240 and a cost of $4.50. EZ-KIT Lite evaluation kits ($199) include an evaluation suite of ADI’s VisualDSP++ development environment