A real-time high speed digital data logger for embedded systems

Measuring the performance of CPU based avionic and automotive systems is critical to their development and evolution. PC-based verification tools rely on measurement data collected from such embedded targets. The Rapita System's RTBx digital data logger provides an efficient way to collect and time-stamp real-time data from a wide variety of embedded targets, over many weeks if necessary. .

Who is the customer?

Rapita Systems Ltd. is a UK-based company developing innovative verification solutions for customers in the high-criticality avionics and automotive electronics industries. Rapita Verification Suite (RVS) helps to reduce the cost of measuring, optimizing and verifying the timing performance of critical real-time embedded systems, so improving test effectiveness.

Application Details

CPU embedded systems communicate their commands and data along digital bus networks most commonly 8, 16 and 32 bits wide. Successful execution of code and timing performance are critical factors. Being able to track down run-time problems across different CPU based systems using an easy-to-use single generic device clearly provides a superior solution to many traditional data loggers and logic analysers, which can be CPU specific as well as complicated to configure. An essential part of the task is collection and storage of time-stamped trace data and where collection extends too many days, even weeks, so a deep storage facility within the device is important.

RVS analyses code execution trace data collected from the target by the RTBx. This provides a complete timing and coverage analysis solution, which is essentially a thorough testing of embedded systems source code program behaviour.

Requirements

• Digital data width 8, 16 and 32 bits
• Sampling rate up to 100MHz (8 and 16 bits), 50 MHz (32 bits)
• High speed data streaming to local hard drive (FIFO Mode)
• Windows and Linux operating platform support
• Programming in Ada (for the development stage)
• Installation into rack mount 19-inch chassis

Solution

The M2i.7000 series of digital I/O cards from Spectrum Instrumentation GmbH were chosen as a desirable component, due to the versatility of having models with 8/16 bit and 32bit I/O ports as well as a very high data acquisition speed (up to 125MHz).

This allows the RTBx Data Logger to be configured to a whole range of automotive and avionic embedded CPU based systems with varying data bus configurations. Also the Spectrum M2i card's adjustable sampling rates and extended data streaming functionality (FIFO mode) allows digital trace capture over several weeks or more. The RTBx Data Logger utilises the M2i card within a special industrial 19-inch rack computing platform and integral deep data storage facility. Connection to the RTBx Data Logger is easily performed from its rear panel via a ribbon cable to the dedicated output port on the embedded system, which is the source of data (instrumentation points) every few CPU machine code cycles. An alternative connection can also be made to the address bus of the system under test, where the user can write a small instrumentation point routine to provide the data at a specific address. The front panel provides a neat LCD display showing logging status, logging data, estimated recording time, network (IP) address and software version. The RTBx Data Logger can be used straight out of the box with the target system, with the further facility of control via an Ethernet connection using a Windows or Linux Host running the Rapita Systems graphical user interface. RTBx is designed to work hand-in hand with RVS

This combined solution provides the basis for products that can evolve to keep pace with the future challenges of more advanced CPU embedded system design, minimising the time and effort in their development, implementation and optimisation

Update

In 2017 the RTBx logger evolved to capture data bus information from even faster systems. This was possible by using the new generation M4i.77xx-x8 series card, which has a 250 MHz data sampling speed capability and differential (LVDS) inputs. An even faster version of the M4i card is capable of 720 MHz and Rapita Systems recently announced the development of a new RTBx Logger capable of working at this higher speed.

Links to more information

• RTBx Data Logger web page at Rapita Systems
• RTBx Data Logger PDF information sheet.