Design Article
High-speed measurements for electric, hybrid vehicles
Alfred Kless, Vector Informatik
3/11/2013 3:40 PM EDT
Data trace concept for the current Infineon TriCore
A concept comparable to Nexus Class 3 may also be used for DAP. This involves reserving a 256 kByte memory range of the ED-RAM (Emulation Device RAM) for measurement data acquisition. In contrast to the 100 MByte/s of the Nexus Class 3 concept, the trace transmission rate for raw data must be limited to 5 MByte/s; just 4 pins suffice instead of 25 pins. A maximum of four RAM monitoring windows may be configured. They must be configured so that there is no overrun of the trace data. Generally, this permits monitoring of just 10–20 kByte of memory instead of 512 kByte and measurement of signals in this memory without processor loading. Signals outside of these trace monitored memory areas can be measured by the RAM copy method.
Advantages of the Infineon DAP data trace solution:
• The maximum measurement data rate of 3 Mbyte/s is a factor of 3 larger than in the RAM copy method.
• The microcontroller is not loaded by the measurement.
• All known PWM drive signals can be measured at a 100 kHz sampling rate without any problems.
Data trace concept for future Infineon controllers
In the next generation of microcontrollers, Infineon is also offering the latest generation Device Access Port (DAP). One advantage lies in its higher raw data transmission rate, which is now 20 MByte/s in contrast to the previous 5 MByte/s. This is attained by the higher frequency of 160 MHz at the DAP interface instead of the previous 80 MHz and by a new type of three-line concept, which permits parallel transmission on two lines.
The greatest improvement to the DAP2 interface is that it now lets users set up hardware-based data trace filters with extremely fine granularity. This significantly reduces the transmission of unnecessary data trace information from the microcontroller to the POD. Despite the maximum measurement data rate of 10 Mbyte/s, it is only necessary to process 15 instead of 100 Mbyte/s of raw data (Figure 3). Due to the considerably reduced requirements for processing the measurement data, cost-optimized measuring instrumentation can be used for DAP2.
Summary
Many aspects of modern drive concepts for vehicles with pure or hybrid electric motors make it necessary to develop new strategies for measurement data acquisition. Existing measuring instrumentation concepts for internal ECU signals often reach their limits in terms of data rate or sampling rate. The sampling rates of up to 100 kHz that are necessary for electric drive systems can be implemented for existing and future microcontrollers using the VX1000 measurement and calibration hardware from Vector. Over the course of this year, new controller generations will be available from Freescale and Infineon, which can perform their tasks with a data trace that requires significantly fewer connection pins. In combination with the high-speed VX1131 measurement module from Vector they will enable measurement data rates of 30 Mbyte/s without CPU loading.
In the case of Infineon, DAP2 with finely granulated signal filters in the microcontroller make it possible to reduce the raw data stream from 100 to 15 Mbyte/s, which permits the use of very cost-efficient measurement hardware to achieve high data rates. When used with the ASAM-standardized XCP on Ethernet as the PC interface, the measurement and calibration hardware is also ideal as a flexible and powerful bypass solution with short latency times.
About the author
After graduating from the University of Applied Science Esslingen with a degree in Electrical Engineering, Alfred Kless initially worked for Alcatel where his roles included team leader for software development and business development of test systems.
Since May 2004, he has been employed at Vector Informatik in Stuttgart as Business Development Manager for the product lines “Measurement & Calibration” and “Network Interfaces.”
All figures: Vector Informatik GmbH
Courtesy of EETimes Europe
Related posts
A concept comparable to Nexus Class 3 may also be used for DAP. This involves reserving a 256 kByte memory range of the ED-RAM (Emulation Device RAM) for measurement data acquisition. In contrast to the 100 MByte/s of the Nexus Class 3 concept, the trace transmission rate for raw data must be limited to 5 MByte/s; just 4 pins suffice instead of 25 pins. A maximum of four RAM monitoring windows may be configured. They must be configured so that there is no overrun of the trace data. Generally, this permits monitoring of just 10–20 kByte of memory instead of 512 kByte and measurement of signals in this memory without processor loading. Signals outside of these trace monitored memory areas can be measured by the RAM copy method.
Advantages of the Infineon DAP data trace solution:
• The maximum measurement data rate of 3 Mbyte/s is a factor of 3 larger than in the RAM copy method.
• The microcontroller is not loaded by the measurement.
• All known PWM drive signals can be measured at a 100 kHz sampling rate without any problems.
Data trace concept for future Infineon controllers
In the next generation of microcontrollers, Infineon is also offering the latest generation Device Access Port (DAP). One advantage lies in its higher raw data transmission rate, which is now 20 MByte/s in contrast to the previous 5 MByte/s. This is attained by the higher frequency of 160 MHz at the DAP interface instead of the previous 80 MHz and by a new type of three-line concept, which permits parallel transmission on two lines.
The greatest improvement to the DAP2 interface is that it now lets users set up hardware-based data trace filters with extremely fine granularity. This significantly reduces the transmission of unnecessary data trace information from the microcontroller to the POD. Despite the maximum measurement data rate of 10 Mbyte/s, it is only necessary to process 15 instead of 100 Mbyte/s of raw data (Figure 3). Due to the considerably reduced requirements for processing the measurement data, cost-optimized measuring instrumentation can be used for DAP2.
Figure 3: In the data trace concept, fine grain filters reduce the raw data stream to 15 Mbyte/s over the DAP2 interface
Summary
Many aspects of modern drive concepts for vehicles with pure or hybrid electric motors make it necessary to develop new strategies for measurement data acquisition. Existing measuring instrumentation concepts for internal ECU signals often reach their limits in terms of data rate or sampling rate. The sampling rates of up to 100 kHz that are necessary for electric drive systems can be implemented for existing and future microcontrollers using the VX1000 measurement and calibration hardware from Vector. Over the course of this year, new controller generations will be available from Freescale and Infineon, which can perform their tasks with a data trace that requires significantly fewer connection pins. In combination with the high-speed VX1131 measurement module from Vector they will enable measurement data rates of 30 Mbyte/s without CPU loading.
In the case of Infineon, DAP2 with finely granulated signal filters in the microcontroller make it possible to reduce the raw data stream from 100 to 15 Mbyte/s, which permits the use of very cost-efficient measurement hardware to achieve high data rates. When used with the ASAM-standardized XCP on Ethernet as the PC interface, the measurement and calibration hardware is also ideal as a flexible and powerful bypass solution with short latency times.
About the author
After graduating from the University of Applied Science Esslingen with a degree in Electrical Engineering, Alfred Kless initially worked for Alcatel where his roles included team leader for software development and business development of test systems.
Since May 2004, he has been employed at Vector Informatik in Stuttgart as Business Development Manager for the product lines “Measurement & Calibration” and “Network Interfaces.”
All figures: Vector Informatik GmbH
Courtesy of EETimes Europe
Related posts
. Maximizing savings at cell sites through deployment of hybrid energy solutions
. Slideshow: Paris auto show drives electric
. How hybrid electric vehicles can pay off
. Hybrid and module technology for high-reliability applications
. Advanced power switches boost micro hybrid emissions gains
. PSA unveils air-powered car
. Testing hybrid engine technology
. Updated: Valeo makes your car engine hybrid
. Ultracapacitors: Best Option for EV Energy Storage Technology
|
|
|
|
|
Navigate to related information