Playing With Floating Point and Low Cost DSPs
F2806x block diagram
F2806x controlSTICK
F2806x controlCARD
Texas Instruments is looking to make the job of digital developers talking motor and power control easier with low cost DSPs like their new TMS320F2806x Piccolo (Fig. 1). The trick is to include new hardware including floating point support along with a Viterbi Complex Math Unit and Control Law Accelerator. These provide a considerable performance boost. This makes it possible loops to handle challenges like power line communications (PLC) protocols and modulation schemes. The Piccolo line already handles a range of motor control and lighting control applications (see LED Controller Kit Covers All The Bases).
The TMS320F2806x Piccolo runs at 80 MHz and supports integer and fixed point operations in addition to floating point support. The Viterbi Complex Math Unit (VCU) adds 75 math instructions tailored to acceleration of communications algorithms. The chips have up to 100 Kbytes of RAM and 256 Kbytes flash.
The optional Control Law Accelerator (CLA) is an independent, 32-bit floating-point processor core. It runs in parallel with the C28x core. It can handle low level control loops efficienctly. It is designed to offload the other core and it has direct access to peripherals.
Peripherals include 150ps resolution PWMS. On the analog side there are 3 Msamples/s 12-bit ADC and 3 comparators with a 10-bit referrence. Communication interfaces include serial ports, USB 2.0 full-speed (host and device), and CAN. The chip has DMA support.
Development software includes controlSUITE (see Texas Instrument's controlSuite Streamlines Motor Control Development) that includes math libraries with source code in addition to sample applications. The IQmath library is also provided. The development environment is Texas Instruments' Code Composer Studio.
Texas Instruments provides a range development tools. The low-cost F2806x controlSTICK (Fig. 2) plugs into a USB port and can be plugged into an application board. The controlCARD (Fig. 3) is a module that can be used for evalation and plugs into a number of reference development platforms from TI. It can also be used in production applications.
The Piccolo F2806x floating-point MCUs start at $4.95 and available in 80 and 100 pin packages. The F2806x controlSTICK is $39. The F2806x Experimenter's Kit is priced at $89.00. They include a copy of Code Composer Studio that has no compiler or memory limitations. The F2806x controlCARD is priced at $59.
