Embedded Development

VisSim/DSP
Vissim/ECD ePWM block properties

Dramatically Shorten Design Cycles with Model-Based Development

VisSim/Embedded Controls Developer (VisSim/ECD) lets you perform Model-Based Design to rapidly develop control systems. This means that you can simulate your system off-line using bit true fixed-point blocks controlling a floating-point plant model. Once verified against a virtual plant, the control subsystem can be selected for automatic code generation and run on the embedded target against the real plant, while communicating in real time to the PC for interactive gain changes and digital scope plotting. VisSim supports the latest C2000 and MSP430 digital microcontroller chips from Texas Instruments.

Embedded Support

The TI DMC block set is a VisSim block version of Texas Instruments Digital Motor Control function library. The TI DMC block set includes:

  • PID Regulator with saturation
  • Space vector waveform generator
  • Park and Clarke transforms
  • Encoder speed estimator
  • Flux estimation and sensorless PMSM sliding mode position estimator
  • Volts to Hertz Profile These blocks can be used in both simulation and code generation to create efficient embedded controllers.
VisSim/DSP
VisSim controlled PMSM phase voltages

The VisSim/Fixed-Point block set includes the following blocks:

sumconstant1/zsqrtatan2
multiplysignsampleHoldsinnegate
divideabsolute valuemergecostable lookup
convertcaseIIR and FIR FiltersPIDBoolean

An Auto-Scaling option determines the optimal radix points for each block to avoid overflow and maximize precision. The display of a minimum and maximum value for each block for determining "headroom" for radix point settings. Configurable word length.

Efficient Code Generation

VisSim/ECD's unmatched code generation efficiency allows faster sampling and use of lower cost parts. For instance, a VisSim diagram for full sensorless field-oriented control of a permanent magnet synchronous motor (PMSM) with signal buffering vectors for debugging uses only 3k flash and 1k RAM. At 20kHz control sample rate on the TI 60MHz low-cost Piccolo microcontroller, only 34% of CPU is utilized. This efficiency allows multiple axis control or additional supervisory control.

RTOS Support

VisSim/ECD includes its own highly efficient native RTOS environment with primary control rates up to 1MHz. VisSim supplies simple graphical interrupt handler creation, as well as custom rate, pre-emptable background tasking. VisSim target support includes automatic on-chip peripheral coding, simple dialog based configuration, interactive data exchange for nonintrusive debugging, and real-time CPU utilization calculation.

Foreign RTOS Support

VisSim/ECD also has an option to integrate with a foreign RTOS. In this mode, VisSim/ECD it will generate two functions: an init function to be called at boot time, and a periodic control function to be called by the RTOS at the designed rate. This allows integration with DSP/BIOS or any other RTOS.

I am using VisSim 7.0 almost every day. As a developer of high and very-high power digitally-controlled power supplies, I don't have the time to get too much into the nitty gritty of the DSC; therefore, I find the VisSim environment ideal for me. I am very pleased with the functionality and new blocks that have been added for the F280x controller from TI. VisSim/ECD is capable of creating a complete control algorithm for the F280x directly from the VisSim environment. I would like to thank you for your support of VisSim and the continuing development of your software
Tony Boon
Digital Power Engineer
CEG Elettronica

Code Composer Integration

VisSim/ECD comes with a Code Composer Studio plug-in that automatically creates a CCS project from VisSim-generated code. The project includes the generated .C file, as well as the necessary VisSim support libraries, include files, and compile options.

Full On-chip Peripheral Support

VisSim/ECD target support blocks let you configure and generate code for ADC, PWM, GPIO, CAN, SPI, SCI(RS232,UART), I2C, capture, watchdog and quadrature encoder on-chip peripherals.

JTAG HotLink

The VisSim JTAG HotLink automatically downloads and communicates in real time with your compiled diagram as it runs on the target. It lets you use the VisSim GUI on the PC to change parameters and plot embedded target responses while it runs.

Benefits

  • Faster debug with buffered waveform monitoring and interactive on-target gain change
  • Use of higher level debugged modules for quicker prototyping
  • Faster time to market
  • Lower overall design and prototyping costs
  • Easier transfer of knowledge from one engineer to the next

Case Study

EMS Electric Bike