High Speed RTDX (HSRTDX)
High-Speed RTDX (HSRTDX)
|Warning:||As of 6/24/2010 HS-RTDX is no longer supported. Alternative transports should be considered for the acquision of data, such as serial ports and ethernet. If you are currently using the technology and have no issues, there is no need to change. However, no action will be taken for support inqueries.|
There are two types of Real Time Data eXchange (RTDX). XDS510-class emulators support an existing form of RTDX called "standard" RTDX that is capable of data rates from 10 KBytes per second and higher. The XDS560 also supports standard RTDX, boosting those speeds to as high as 130 KBytes/second. In addition, the XDS560 offers High Speed RTDX (HSRTDX) for enabled processors with bandwidth of over 2 MBytes/second. High-speed RTDX bandwidth enables applications such as streaming video, ADSL, and hard disk drive. This provides an unprecedented level of real-time visibility into running applications.
High-speed RTDX requires:
- a special high-speed RTDX peripheral on the target device,
- an XDS560-class emulator, and
- linking the application with the high-speed RTDX library.
All of the capabilities of RTDX are standard between RTDX and high-speed RTDX. None of the RTDX calls made in the application need to change at all to move from using standard RTDX to using high-speed RTDX. RTDX is implemented with a small monitor (less than 2 Kilobytes for standard RTDX, and approximately 4 KBytes for high-speed RTDX) that is included as a part of DSP/BIOS. In fact, RTDX is used as the underlying transport mechanism for DSP/BIOS Real-Time Analysis, so that when you perform DSP/BIOS Real-Time Analysis (RTA), you are also running the RTDX data link to bring the data up from the target for visualization in the Real-Time Analysis display. With the small monitor RTDX is very non-intrusive, as it requires a very small amount of CPU overhead to perform the procedure calls to either transmit or receive data. The application makes calls to RTDX functions as needed to log the data back to the host over the JTAG connection, and the data can then be assembled in either continuous or snapshot modes of logging the data.
The RTDX architecture consists of a combination of hardware and software components, from the on-chip JTAG emulation logic, to the emulator hardware, the JTAG interface, and the RTDX library software on the host and the target. To transfer data from the target to the host, the target application calls the RTDX Target library, the data is copied to a buffer, and then scanned up to the host via the emulation hardware in real time. On the host the data is either recorded to disk ("saved"), or buffered internally and delivered to the host application via Code Composer Studio ("live"). RTDX can also be run with the simulator, and can be used with multiple homogeneous or heterogeneous targets simultaneously, with no change to the RTDX calls being made from the target application. In this situation RTDX divides up the available RTDX bandwidth between the multiple channels.
RTDX runs asynchronously, in real-time, between the target and the host. RTDX data can be viewed through the industry-standard Microsoft Component Object Model (COM) API, allowing data to be streamed into any other COM-compliant applications like Microsoft Excel, Visual Basic, or signal processing and acquisition packages such as MATLAB from the MathWorks, or LabVIEW from National Instruments. COM is an interfacing technology that enables separate, independent applications to communicate with each other. In fact, multiple host applications can run simultaneously if desired, all receiving or transmitting RTDX data in real time.
With the Microsoft COM interface, data acquisition and analysis packages such as LabVIEW can be used together with RTDX to check the correctness of embedded DSP algorithms. This can be done by comparing the results of the embedded algorithm with those obtained from a known correct algorithm from a standard data analysis or signal processing algorithm. With advanced packages like MATLAB and LabVIEW a direct comparison of the results can be done visually, rather than comparing hundreds or thousands of numbers from the two different implementations.
RTDX can also be used to create custom visualizations of embedded applications, using RTDX to display various aspects of a running system. This is accomplished by streaming the data on the status of the system to the host, where the data can be received through the COM-compliant interface and displayed with graphical display tools. Custom displays featuring gauges, meters, and other tools can be enabled with real-time RTDX data from the embedded application for debugging, testing, and demonstrations, before the entire system has been completed.