I’m looking to set up a loopback so that data sent from an Aardvark^™ I2C/ SPI Host Adapter is echoed. How can I do that?

Thanks for your question! To echo data, you can set up a loopback mode by using two Aardvark I2C/SPI Host Adapters and two instances of the Control Center^™ Software to send traffic between the two Aardvark host adapters.  One adapter will be configured as the master, and the other adapter will be configured as a slave.  The slave unit can then be programmed with the message to “echo” when pinged by the master unit.

Following are instructions to set up and verify a loopback mode in SPI (the instructions are similar for the I2C protocols):

1. Connect the Master I2C/SPI connector of one Aardvark adapter to the Slave I2C/SPI connector of the other Aardvark adapter.
2. Connect the Aardvark–Master USB port to USB port 1 of the computer.
3. Connect the Aardvark–Slave USB port to USB port 2 of the computer.
4. Launch the Control Center Software for the Aardvark-Master on the computer. To do so:
   1. Click Configure Aardvark Adapter → Select Aardvark-Master -> Click OK.
   2. Click Aardvark → Enabled Target Power.
   3. Use the SPI Control section.
   4. Click Master.
   5. Choose the following parameters: Polarity: Raising/Falling; Phase: Sample/Setup; Bit Order: MSB; SS Polarity: SS Active Low; Bit Rate: 1000KHz.
   6. Type 0A 0B 0C 0D in the MOSI message.
5. Launch the Control Center Software for the Aardvark-Slave on the computer. To do so:
   1. Click Configure Aardvark Adapter → Select Aardvark-Slave -> Click OK.
   2. Use the SPI Control section.
   3. Click Slave.
   4. Choose the following parameters: Polarity: Raising/Falling; Phase: Sample/Setup; Bit Order: MSB; SS Polarity:SS Active Low; Bit Rate: 1000KHz.
   5. Type 01 02 03 04 in the MISO message → Click Set MISO → Click Enable.
6. In the Control Center Software for the Master, click Send and then verify the following:
   • The transaction log in the (Master) Control Center Software  shows that the Aardvark – Master sent 4 bytes of 0A 0B 0C 0D, and received 4 bytes of 01 02 03 04.
   • The transaction log in the (Slave) Control Center Software shows that the Aardvark-Slave received 4 bytes of 0A 0B 0C 0D, and sent 4 bytes of 01 02 03 04.

For additional information, please refer to the following documents:

Aardvark I2C/SPI Host Adapter Quick Start Guide
Aardvark Adapter User Manual
Control Center Software User Manual
Total Phase Products
Product Selector Guide

Support Question of the Week: Using the Beagle I2C/SPI Protocol Analyzer, How Can I Export Captured Data from the Data Center Software to Process the Data More Easily?

When viewing SPI and I2C transfers, captured data using the Beagle^TM I2C/SPI Protocol Analyzer and the Data Center^TM Software, how can I calculate the average bus clock speed for the transactions?

The Data Center Software shows me the measurements, but the format of the data includes characters such as “μs” to denote the time, which cannot be processed in an Excel sheet for numerical calculations. What are my options for this?

Thanks for your question! There are three ways to process the captured data:

• You can use the delta time value and the bandwidth value displayed in the lower left-hand corner of the Data Center Software window for the time and bandwidth between two transactions, as shown below in Figure 1. Simply click to select one transaction and hover over another transaction to see the time and throughput. For more information, please refer to section 5.1.1 in the Data Center Software User Manual.
• You can export the Data Center transaction log to a csv file, and then use Excel to remove the “μs” and process the data.  For other applications, the transaction log can also be exported as bin, xml or kba files. For more information, please refer to section 4.12 of the Data Center Software User Manual.
• You can also use Beagle API Software to control the Beagle protocol analyzer, and to write a custom program for your specifications. Our API comes with support for multiple OSs (Windows, Linux, and Mac) and multiple languages (C, Python, Visual Basic, and C#), and includes examples. We recommend using the Python bindings as it is a simple language, and a good option for scripting. For more information about API software, please refer to section 6 of the Beagle Protocol Analyzer User Manual.

Figure 1: Data Center Software

 For more information, please refer to the following documents:

Beagle I2C/SPI Protocol Analyzer Quick Start Guide
Beagle Protocol Analyzer User Manual
Data Center Software User Manual
Total Phase Products
Product Selector Guide

We hope this answers your question. If you have other questions about our protocol analyzers or other Total Phase products, feel free to email us at sales@totalphase.com or submit a request for technical support.

I need to simultaneously monitor both the I2C bus and the SPI bus. I  have one  Beagle^TM I2C/SPI Protocol Analyzer, as well as one Beagle USB 480 Protocol Analyzer. The setup  I need:

• One USB analyzer (Beagle 480)
• One SPI analyzer
• One  I2C analyzer

Is it possible to have two Data Center^TM Software instances running one analyzer  to support both protocols,  or do I need a second SPI/I2C analyzer?

Thanks for the question! The Beagle I2C/SPI analyzer can monitor the I2C bus and the SPI bus. However, the Beagle I2C/SPI analyzer cannot monitor I2C and SPI buses at the same time. For your application, we recommend using two Beagle I2C/SPI analyzers, one Beagle 480 analyzer, and three Data Center instances. The setup would be as follows:

• One Beagle USB 480 monitors USB
• One Beagle I2C/SPI monitors I2C
• Another Beagle I2C/SPI monitors SPI
• Three Data Center Software instances would support each protocol analyzer.

Using the Data Center Software, each Beagle I2C Protocol Analyzer can be configured as follows:

 To configure a Beagle I2C/SPI Protocol Analyzer for I2C:

1. Click Analyzer > Device Settings.
2. Choose I2C in the Capture Protocol option.
3. Choose 10MHz for the Sampling Rate option.
4. Enable Target Power and I2C Pull-ups based on the parameters of the target system.
5. Click OK to close the Device Settings.

Figure 1: I2C Protocol Configuration

To configure a Beagle I2C/SPI Protocol Analyzer for SPI :

1. Click Analyzer > Device Settings.
2. Choose SPI in the Capture Protocol option.
3. Choose 50MHz for the Sampling Rate option.
4. Enable Target Power based on the parameters of the target system.
5. Configure the MSB First, Rising edge, and Slave Select polarity based on the parameters of the target system.
6. Click OK to close the Device Settings.

Figure 2: SPI Protocol Configuration

For more information, please refer to the following documents:

Beagle I2C/SPI Protocol Analyzer Quick Start Guide
Beagle Protocol Analyzer User Manual
Data Center Software User Manual
Total Phase Products
Product Selector Guide

We hope this answers your question. If you have other questions about our Beagle protocol analyzers or other Total Phase products, feel free to email us at sales@totalphase.com or submit a request for technical support.

I am using the Aardvark^TM I2C/SPI Host Adapter with a PMBus (Power Management Bus) device. The protocol of the PMBus device requires a Repeated Start (Sr). The Read Byte protocol looks like this:

S-SlaveAddress(7)-Wr(1)-Ack-Command Code(8)-Ack-Sr-SlaveAdress(7)-Rd(1)-Ack-DataByte(8)-Ack-P

I do not want a Stop between the Write and Read portions of the transaction. Can the Control Center^TM Software GUI accommodate this? The only obvious buttons are Write and Read. I see the Aardvark^TM Software API has a function called "i2c_write_read". I need to program the software to read with a repeated Start (Sr)  – which application would work best for this?

Thank you for your question! The Control Center Software was recently updated to v3.56. This new version includes features that match your requirements. To update the software, we recommend you install the latest Control Center v3.56 for your computer.

Figure 1: Control Center Software

The Control Center v3.56 "I2C Master Register Read" option can be used for your system requirements. The typical protocol to read a register on an I2C device performs an I2C write with the register address, which is followed by a repeated start and an I2C read. The "I2C Master Register Read" feature provides a way to do this in one operation. For detailed information, please refer to section 4.1.2 of the Control Center User Manual.

The Aardvark API function "Master Write-Read (aa_i2c_write_read)" writes a stream of bytes to the I2C slave device followed by repeated start and a read from the same slave device. For additional information please refer to section 5.5.3 of the Aardvark Host Adapter User Manual.

For additional information, please refer to the following documents:

This week’s article is about using a Cheetah^TM SPI Host Adapter for programming SPI EEPROM and flash devices, which can be done using Cheetah^TM GUI Software, Flash Center^TM Software, or the Cheetah^TM Software API. This example will use the ST Micro SPI Flash M25P32 mounted on an SPI Flash Demo Board, and the Flash Center Software to program SPI flash devices and then read back the data.

Using the Cheetah SPI Host Adapter with the Flash Center software makes it easy to program SPI EEPROM and SPI Flash devices. With one Flash Center Software click, erase, program, and verify an entire device. Note – with some modification, this example can be used for other devices.

Overview of the Flash Center Software

In this example, the Cheetah adapter erases, programs and reads the M25P32. Here the Cheetah adapter is the SPI master and the SPI flash on the SPI Flash Demo board is the SPI slave.

First, we will go over the operations options provided by Flash Center. Specifically, there are three programming modes: Program + Verify, Program, and Program (No Erase). In addition there are Read Device, Verify, and Erase operations.

• Program + Verify - Writes data to one or more attached memory devices and then reads back the data to verify it for correctness. If the device is an SPI Flash, an erase cycle will be performed first. The erase will cover only those sectors, which will be written. Note that it is possible to erase more data than is written if a write ends in the middle of a sector. A warning will be logged if this is the case. Also, if the data to be written is large enough to require the entire device to be erase, and the memory device has an “erase all” instruction, the software will use the “erase all” instruction.
• Program - Writes data to the device, but does not perform the verification step. If the device is an SPI Flash, an erase cycle will be performed first, with the same caveats as Program + Verify.
• Program (No Erase) - A special mode for SPI Flash devices. It writes data to the device, but does not perform an erase cycle. This is useful if multiple memory images are to be programmed to the device. Use FF as the pad value when loading each memory image to avoid corrupting previously written data. Because the device may have been programmed prior to this operation, it does not perform the verification step.
• Read Device - Reads the contents of the selected device and replaces it in the current contents in the data buffer.
• Verify - Verifies the contents of the selected devices against the contents of the data buffer.
• Erase - Allows the user to erase the entire memory device or allows the erasure of portion of it. For partial erasure, users can specify the start addresses and length in the erase parameters dialog as either a decimal value or as a hexadecimal value.

Details about the M25P32 SPI Flash

The 32 Mbit (4M bytes) SPI Flash M25P32 found on the SPI Flash Demo Board has 64 sectors. Each sector has 256 pages or 65,536 (64K, 0x10000) bytes. Each page has 256 bytes. Therefore, the memory has 16,384 pages or 4,194,304 (0x400000) bytes. The entire memory can be erased using the Bulk Erase instruction, or one sector at a time using the Sector Erase instruction. For reference, the M25P32 instructions list and memory map are provided below. For additional information about the SPI Flash M25P32, please refer to the M25P32 datasheet.

Figure 1: M25P32 Memory Map

 

Figure 2: M25P32 Instructions List

 

Part 2 of this article provides the instructions for programming an SPI device.

For more information, please refer to the following documents:

Cheetah Adapter User Manual
Flash Center Manual
High-Speed Flash Demo Board User Manual
Programming SPI Flash Using Cheetah Adapter and Flash Center
Total Phase Products
Product Selector Guide

We hope this answers your question. If you have other questions about our Cheetah, SPI Host Adapter or other Total Phase products, feel free to email us at sales@totalphase.com or submit a request for technical support.

This article is Part 2 of an example of programming SPI Flash devices using the Cheetah^TM SPI Host Adapter and the Flash Center^TM Software. Part 1 provides an overview of the programming modes of the Flash Center Software, and the memory map and commands of the STMicro M25P32 device used in this example.  In this post, Part 2, we’ll go over exactly how to use the software along with the host adapter to program SPI Flash devices.

Instructions to read and write to SPI Flash device:

1. Connect the Cheetah adapter to the computer via the USB connector.
2. Connect the Cheetah adapter to the SPI Flash Demo Board via the I2C/SPI connector.
3. Launch the Flash Center Software.
4. Connect the Cheetah adapter to the Flash Center Software.  To do so:
   1. Click Adapters > Add Adapters.
   2. Select the Cheetah adapter.
   3. Click Add to connect to the adapter.
5. Enable Target Power.
6. Click Operations > Choose Target and choose M25P32.
7. Configure Bit Rate to 40 MHz
8. Read the memory device. To do so:
   1. Click Operations > Read Target
      Figure 1: Cheetah Adapter Reads From M25P32

       

9. Program and then read the M25P32. To do so:
   1. Click Operations > Program + Verify > Click OK.
   2. Click Operations > Read Target.

Figure 2: Cheetah Adapter Writes to M25P32 and Reads the Results

For more information, please refer to the following documents:

 Cheetah Adapter User Manual
Flash Center Manual
High-Speed Flash Demo Board User Manual
Programming SPI Flash Using Cheetah Adapter and Flash Center
Total Phase Products
Product Selector Guide

We hope this answers your question. If you have other questions about our Cheetah, SPI Host Adapter or other Total Phase products, feel free to email us at sales@totalphase.com or submit a request for technical support.

I have a question about using the Beagle^™ USB 480 Protocol Analyzer. In our latest designs, many of the USB links are embedded – chips are interconnected on the same circuit board. My question: How do we attach the analyzer to an embedded USB link?

Thanks for your question! You can cut a USB and use the individual wires to tap onto to any leads on the board or solder the wires to the USB lines. This information is available in section 2.2 of the Beagle Protocol Analyzer User Manual and the knowledge base article Monitoring an embedded USB with a Beagle USB Protocol Analyzer.

In section 3.1.1 of the Beagle Protocol Analyzer User Manual, Figure 40 shows the four  main architectures for connecting devices to the Beagle protocol analyzer. Item (d) of Figure 40 shows connecting the Beagle protocol analyzer to an embedded system. Refer to Figure 1 below. In this case, you can use a parallel connector to tap off the lines, and then plug the tapped off cable to either the Target Host or the Target Device port of the Beagle analyzer (the ports are equivalent).

Figure 1: Monitoring an Embedded System

 

More information is provided in the knowledge base article Monitoring an embedded USB with a Beagle USB Protocol Analyzer.  A summary follows:

• The D+/D- signal path of a USB does not have to be broken to be monitored by a Beagle USB protocol analyzer.
• The VBUS, GND, D+, and D- lines can be connected to either the Type A or Type B connector on the Beagle analyzer using "T" connections.
• The method of connecting the Beagle analyzer to the embedded bus will vary depending on how accessible the signals are on the target system. A USB cable may need to be cut open to connect the wires directly to the target system.
  • If the signal lines are accessible through a header or test pads, then the connection to the Beagle protocol analyzer is straightforward.
  • If the signals are not easily accessible, the wires may need to be soldered directly to IC pins or to copper traces on the printed circuit board, and then connect to the Beagle protocol analyzer.

For more information, please refer to the following documents:

Beagle Protocol Analyzer User Manual
Monitoring an embedded USB with a Beagle USB Protocol Analyzer
Total Phase Products
Product Selector Guide

We hope this answers your question. If you have other questions about our Beagle protocol analyzers or other Total Phase products, feel free to email us at sales@totalphase.com or submit a request for technical support.

Q: For my application, I’d like to conduct real-time audio testing. I am using the Aardvark^TM I2C/SPI Host Adapter along with the Python API to deliver SPI data in packets of 8 bytes. I am trying send my 8-byte packet out every 1ms, but it appears the minimum overhead of the aa_spi_write() call is 2ms. I have not found a limitation in my Python script - the loop is much faster than 2ms. However, when I look at the transaction on a logic analyzer, there is a significant amount of time between the packets, as shown below.

Figure 1: SPI Packet Timing with Latency

About the test I’m running:

Data is sent in packets. Each 8-bit chunk is one block of compressed audio, and I need to send them at 1ms intervals. I cannot send the entire array of data in one huge transaction.  How can I make this run faster - overcome latency?

Thanks for the question! The USB interface on the Aardvark^TM I2C/SPI Host Adapter is full-speed USB (12 Mbps) – on the USB, it sends one SOF every millisecond. However, the Cheetah^TM SPI Host Adapter has a high-speed USB interface – on the USB link, it sends one SOF every 125s.  The Aardvark adapter is a great multi-purpose tool, but for the speed requirements of your SPI application, we recommend using the Cheetah SPI Host Adapter. There are factors that cause latency in data transfer, which are described below.  For more information about timing and USB links, please refer to our knowledge base article USB Background.

 

Figure 1: Aardvark I2C/SPI Host Adapter

 

The Aardvark I2C/SPI Host Adapter is a powerful and economical general-purpose I2C/SPI host adapter The Aardvark I2C/SPI host adapter uses a full-speed USB link between the adapter and the computer, operates bitrates up to 8 MHz as an SPI master and 4 MHz as an SPI slave. The maximum bitrates are achievable within each individual byte - they do not extend across bytes.

There are various overheads and delays that decrease the overall speed of data transfer, such as the SS# assertion to first clock (10 - 20 us), the setup time for each byte (7 - 9 us for SPI masters), and the last clock to SS# deassertion. The Aardvark adapter also has 2ms round-trip latency, which is caused by the full-speed USB link between your computer and the Aardvark adapter.  For additional information about  SPI Signaling Characteristics, please refer to section 2.4 of the Aardvark manual.

 

Figure 1: Cheetah SPI Host Adapter

 

The Cheetah SPI Host Adapter uses a high-speed USB link between the adapter and the computer. Since the Cheetah adapter uses a high-speed USB link, the USB latency is reduced from 2ms to about 250us when using the Cheetah adapter's synchronous interface. The Cheetah host adapter also has an asynchronous interface that may provide additional speed for your application.

The Cheetah SPI Host Adapter operates at higher speeds up to 50 MHz, can provide gapless shifting, and provides more control over the timing of the data that is shifted out.  For additional information about the Cheetah SPI signaling characteristics, please refer to section 2.5 of the Cheetah Host Adapter User Manual. For more information, please refer to the following documents:

Aardvark Adapter User Manual
Cheetah Host Adapter User Manual
USB Background
Total Phase Products
Product Selector Guide

We hope this answers your question. If you have other questions about our host adapters or other Total Phase products, feel free to email us at sales@totalphase.com or submit a request for technical support.

We are working on an automotive application, and we will be using the Komodo^TM CAN Duo Interface. We also have the Data Center^TM Software that was provided with the Komodo.

This purpose of the application is to be able to trouble-shoot the radio outside of the vehicle.  A module that is integrated in the vehicular system controls the radio.  We need to operate the radio in a setup that duplicates the conditions inside the vehicle.  To do so, we need to reproduce the CAN data on the vehicle at both high speed and low speed, so that we can turn the radio on and off under various test conditions.  To reproduce the CAN data, we need to analyze and filter the data while the radio is installed in the vehicle.

What we plan to do:

1. Cut the radio CAN line and then interface the Komodo between the radio and the control module.
2. Listen to the bus line on port 1 of the Komodo.
3. Save, filter and resend the data on port 2 to the radio in real-time.
4. Listen to the reply from the radio on port 2, and both save the radio reply and return the reply to port 1.

Can this be done with the Data Center Software, or do we need a different tool?

Thanks for your question! What you are suggesting is very possible. There are two main ways to utilize the Komodo interface for working with your application.  One method - you can use our GUIs.  You can use the Data Center software to record the data on port 1, and use the same software export it as a *.kba (Komodo GUI Batch File).  Then, using the Komodo GUI, you can open the exported *.kba file and replay the captured data on port 2.

However, for a more automated solution, and to do this for near real-time data, it involves writing an application with our Komodo API or LabVIEW drivers.  Our Komodo API Software allows creating many different scenarios that can work with C, C#, and Python. Many software examples are provided, which you can modify for your specific requirements.

Figure 1: Komodo CAN Duo Interface

 

There are a few things to keep in mind: The two interfaces on the Komodo Duo are treated as separate adapters connected to the same USB connection. Also, the limitations to the response speed will be your software's ability to process the information and to send it back to the Komodo. Our USB interface can handle 40 MB/s of data transfer, which is much faster than the CAN rate and brings the data much closer to real-time.

The other limitation is the USB interface turn-around time of 2ms (1ms out and 1ms back). For more details, please refer to section 3.8.4 of the Komodo Interface User Manual.

For more information about the host adapters and other Total Phase products, please refer to the following documents:

Komodo Interface User Manual
Komodo GUI Software User Manual
Data Center Software User Manual
Total Phase Products
Product Selector Guide

We hope this answers your question. If you have other questions about our Host Adapters or other Total Phase products, feel free to email us at sales@totalphase.com or submit a request for technical support.

I need to analyze and simulate a CAN-driven display system used for elevators. The display receives CAN commands and displays the floor number and other information. I don't know the bus details, such as speed and ID. My question - can the Komodo^™ CAN Duo Interface automatically synchronize with the bus and log the data?

Thanks for your question! You can definitely use the Komodo interface to analyze and simulate your CAN system.  For analysis, you would use the Data Center™ Software along with the Komodo interface to monitor you application. Simply start Data Center, connect to your Komodo interface, and click the “Run Capture” button to start looking at your application’s CAN traffic in real-time.  The Komodo interface will automatically detect the bus speed, and you can analyze the data using our real-time search and filtering features.

Figure 1: Data Center Software View for Data Analysis

For simulating, or sending data on the bus, you can use the the Komodo^TM GUI Software.

The bitrate can be set automatically by pressing the "Auto Bitrate Button". When the button is pressed, a dialog window appears that displays the operations in progress. The Komodo interface will then cycle through the bitrates listed below and determine if any match the bitrate used on the connected CAN bus. Once the bitrate detection operation completes, the pass/fail result is displayed in the progress dialog window. The new bitrate will appear in the Bitrate Field of the toolbar. An example of bitrate information is shown below:

Bitrate List:

•   1000 kHz
•   500 kHz
•   250 kHz
•   125 kHz
•   100 kHz
•   50 kHz
•   25 kHz
•   29 kHz

For more information about setting bitrates, please refer to section 3.1.1 of the Komdoo GUI Software User Manual.

The Komodo GUI Software can export the transaction log to CSV format. For additional information about exporting data, please refer to section 3.1.5 of the Komodo GUI Software User Manual.

 

Figure 2: Komodo GUI Software View for Data Analysis

 

The Komodo API Software has two auto detect functions for bitrates: km_can_auto_bitrate and km_can_auto_bitrate_ext. For details about these functions, please refer to section 5.6.2 of the Komodo Interface User Manual.

For more information about the Komodo CAN Duo Interface and other Total Phase products, please refer to the following documents:

 

Komodo Interface User Manual
Komodo GUI Software User Manual
Data Center Software User Manual
Total Phase Products
Product Selector Guide

 

We hope this answers your question. If you have other questions about our CAN Interface or other Total Phase products, feel free to email us at sales@totalphase.com or submit a request for technical support.

I have been using the Aardvark^TM I2C/SPI Host Adapter and version 1.20 of the Flash Center^TM Software.  
For the Spansion SPI flash device, Spansion chip (S25FL256S), I have been using a Total Phase XML file that I modified for that device.

What new devices does the new version of the Flash Center Software support directly?

Thanks for your question!  We recommend you to use the latest version (v1.24) of the Flash Center Software. Recently, built-in support for your part, the SFL256S, was added – new devices are always being added to Flash Center Software for direct support, as well as other enhancements and new features.

Figure 1: Flash Center Software

Also, since you are working with SPI flash memory, we suggest taking a look at the Cheetah^TM SPI Host Adapter.  It does not have the I2C and slave functionality of the Aardvark adapter, but it is made for very fast SPI programming up to 50 MHz.

Here is a list of the devices that were added to  v1.24 of the Flash Center Software:

• ISSI IS24C04 I2C EEPROM.
• Spansion SPI Flash
  • S25FL-A
  • S25FL1/FL2-K
  • S25FL-S/P
• Micron N25Q SPI flash parts
• Additional Macronix Flash Memory
• Additional SST Flash Memory

Recently, new features were added to Flash Center v1.22. For Memory Device files, 
the addition of SST Auto Address Increment (AAI) programming:

• writeAutoAddressIncrementInstruction
• writeAutoAddressIncrementSize
• writeAutoAddressIncrementTime

For large SPI memory devices, the addition of enabling extended addressing (4B) mode:

• extendedAddressingEnableInstruction

For greater flexibility, user-definable transaction parameters and SPI protocol parameters :

• userTransaction1
• userTransaction2
• userTransaction1WriteEnable
• userTransaction2WriteEnable
• userTransaction1Time
• userTransaction2Time
• spiMode
• spiBitorder
• spiSSPolarity

When the Flash Center Software is updated, the user manual is also updated; changes are listed in section 1.1 of the Flash Center Software User Manual. If the device is not yet supported, you can modify an existing API file for your specific requirements.

For more information, please refer to the following documents:

We are using the Aardvark^TM I2C SPI Host Adapter as an I2C slave to test a master I2C port on another device. It appears the Aardvark adapter is using clock stretch while it is configured as a slave. Can you tell us what causes clock stretching - when we should expect to see that feature?

Figure 1: Aardvark I2C/SPI Host Adapter

Thanks for your question! The Aardvark I2C/SPI Host Adapter supports the I2C clock stretch feature, which is always enabled; clock stretch cannot be disabled. Clock stretching holding the SCL (serial clock) line low can occur when the Aardvark adapter is functioning as a master device or a slave device.

 

Figure 2: I2C Bus

 

Per the I2C specification, both master devices and slave devices can initiate clock stretch. Following are the two reasons for clock stretch to occur:

1. In I2C communication, the master devices controls the clock speed, and will perform a clock stretch when it needs to slow down the clock.
2. Although the master device controls the clock speed, a slave device can perform clock stretching when it needs more time to store a received byte or to prepare another byte to be transmitted.  A slave device can also perform a clock stretch after receiving and acknowledging a byte. This feature allows the slave to force the master into a wait state until the slave is ready for the next byte transfer. For example, a slave microprocessor may need additional time to process an interrupt, get the data and place it in its transmission register; an EEPROM, however, does not have such internal functions, and does not need clock stretching.
   

When the Aardvark adapter is configured to slave mode, it can generate clock stretch when it needs to perform and finish its internal function. For example, the Aardvark adapter can generate clock stretch when it needs more time to store a received byte or prepare another byte to be transmitted. The Aardvark adapter can generate the clock stretch before restart or before start, depending on the configuration, system setup and traffic.

For additional information about clock stretching, please refer to section 3.1.9  of the I2C specification. For more information about the Aardvark I2C Host Adapter and other Total Phase products, please refer to the following documents:

 Aardvark Adapter User Manual
Total Phase Products
Product Selector Guide

We hope this answers your question. If you have other questions about our host adapters or other Total Phase products, feel free to email us at sales@totalphase.com or submit a request for technical support.

We have a Beagle^TM I2C/SPI Protocol Analyzer and are using it with the Level Shifter Board. The target is a 1.8V I2C device and we're trying to set it up with an external power supply - not provide power from the Beagle analyzer. We believe we have it set up correctly, but the Data Center^TM Software shows no activity. Our setup is as follows:

•  The TPWR jumper is removed.
•  All voltage level jumpers removed.
•  The TP240411 10-Pin Grabber Clip Split Cable is connected to the TARGET1 header.
•  The Beagle analyzer is connected to the Analyzer header.
•  To the target, SDA and SCL are straightforward.
•  To power the target side of the level converter board, the NC/+5V grabber is connected to the target's 1.8V supply.

The NC/+5V grabber does have continuity with the TPWR pin at the EXT TGT header area on the Level Shifter, and an oscilloscope shows activity on the SDA and SCL lines, and 1.8 VDC on pin 4 and pin 6 of the TARGET2 header. However, the TARGET LED is not turned on, and the Data CenterSoftware shows no activity. Can you advise us what to look for to troubleshoot this?

Figure 1: Level Shifter Board

Thanks for your question! Your description indicates that the setup correct. The SCL and SDA lines go through the Level Shifter, on which the TPWR pin on the EXT TGT header (pin 13) is connected to the target side of the device. The TPWR is also connected to the TARGET1 and TARGET2 connectors (pins 4 and 6). When properly connected, the TARGET LED illuminates amber.

The one step not described in the setup is enabling the Beagle's target power to provide power to the analyzer side of the level shifter board. This can be verified by looking at the Power LED, which must be lit green. The Level Shifter Board will not work if  the LED is not lit green - the TPWR jumper isolates the analyzer side from the target side power. For more information, please refer to section 3.4 of the Level Shifter Board User Manual.

In the Data Center Software, ensure I2C "Target Power" of the Beagle I2C Protocol Analyzer is selected. For more information about I2C device settings, please refer to section 7.2 of the Data Center Software User Manual.

Figure 1: Check "Target Power"  in Data Center Software

For more information, please refer to the following documents.

Level Shifter Board User Manual
Data Center Software User Manual
Beagle Protocol Analyzer User Manual
Total Phase Products
Product Selector Guide

We hope this answers your question. If you have other questions about our host adapters or other Total Phase products, feel free to email us at sales@totalphase.com or submit a request for technical support.

I will be using the Beagle^TM I2C/SPI Protocol Analyzer to monitor MDIO (Management Data Input/Output).  Can you advise which Total Phase software tool to use to monitor MDIO? That feature does not seem to be available in the most current version of Data Center^TM Software. What are my options?

Thank you for your question! The current version of Data Center Software does not support MDIO. However, a previous version of Data Center Software, v2.20, does support MDIO and can be downloaded – Data Center Software is cross-platform and is supported on Windows, Linux and Mac OS X platforms (we are looking to add MDIO support to a future version of Data Center Software).

 

Figure 1: Data Center Software

 

In addition, all versions of Beagle API Software also support MDIO.  Using the API gives you the advantage of writing custom the software for your specific standards as needed. For more information about the API, please refer to section 6.9 (MDIO API) of the Beagle Protocol Analyzer User Manual.

Following are additional information and guidelines about monitoring MDIO with the Beagle analyzer:

The Beagle analyzer monitors clause 22 MDIO and clause 45 MDIO, and non-intrusively monitors MDIO up to 2.5 MHz.  The Beagle MDIO signal, pin 8, is the management data input/output, and it is bidirectional signal, which is used to transfer data between the STA and the MMD. The Beagle MDC signal, pin 7, is the management data clock, which is a control line that is driven by the STA and synchronizes the flow of the data on the MDIO line.

To properly capture MDIO signals, the sampling rate must be set correctly. For MDIO monitoring, the minimum requirement for the sampling rate is twice the bus bit rate. For additional information about MDIO and how it works, please refer to our knowledge base article MDIO Background.

The Beagle signal level is 3.3V. To monitor a lower voltage MDIO bus, you can use the Total Phase Level Shifter Board.

For more information, please refer to section 1.4 (MDIO Background) and section 2.4 (Beagle I2C/SPI/MDIO Protocol Analyzer) of the Beagle Protocol Analyzer User Manual.

For additional information, please refer to the following documents:

Beagle Protocol Analyzer User Manual
Data Center Software User Manual (most recent version)
Data Center Software User Manual, v2.20
MDIO Background (knowledge base article)
Level Shifter Board User Manual
Total Phase Products
Product Selector Guide

 

We are using the Cheetah^TM SPI Host Adapter with an SPI slave device. This slave device sends FF bytes on MISO as long as it is busy (somewhat similar to  the clock-stretch for I2C), and if it is ready a first byte != FF byte is sent at mark 4. From then on, the data is the valid payload of interest that we want at read-data. The problem we have is that the number of FF bytes varies, and that count is unknown at start of the whole read.

We tried a few combinations with a ch_spi_batch_shift() and ch_spi_queue_array(), but we always get timeouts on the Beagle trace we use. Are the ch_spi_queue_ss() and ch_spi_queue_oe() deassert also needed, or is there another way to accomplish this? How can we filter out the FF bytes with the API software?

Thanks for your question! It is possible to filter the unwanted FF bytes using Cheetah^TM Software API?. To do so, you can modify the API code. Modification is one of the main features of SPI software - it allows you to "tweak" existing software for your specific application requirements. API software is supported for 32-bit and 64-bit versions of Windows, Linux and Mac OS. With Rosetta Language Bindings and shared libraries, the supported 32-bit and 64-bit software languages are C, C#, Python, .Net, VB NEW and VB6. All software downloads are listed on the our Active Software Downloads page.

 

Figure 1: Cheetah API Software

 

Currently, the Cheetah adapter reads all the data including the bad data FFs and the good data AA BB CC DD. For example: FF, FF, FF, AA, BB, CC, DD. Following is an outline of how that could be done:

1. In the C code, filter out (remove) the bad data FFs in the beginning of the data, and keep only the good data. For example: AA, BB, CC, DD.
2. In the C code, provide the user in your GUI only the good data. For example: AA, BB, CC, DD.

For more information, please refer to the following documents:

Cheetah Host Adapter User Manual
Cheetah Software API
Cheetah GUI Software User Manual
Total Phase Products
Product Selector Guide

We hope this answers your question. If you have other questions about our Cheetah SPI Host Adapter or other Total Phase products, feel free to email us at sales@totalphase.com or submit a request for technical support.

I am using the Aardvark^TM I2C/SPI Host Adapter as an SPI master with multiple slave devices. Can you clarify how the  Aardvark API Software command aa_spi_write() works?

Is Slave Select asserted for each byte sent MOSI (master output slave input)?
-or-
Is Slave Select asserted for each byte sent MOSI (master output slave input)?

Thanks for your question!  SPI requires four signals: SCLK, MODI, MISO, and SS. When the SPI implementation has multiple slave devices, each slave device requires a separate SS signal. The SCLK, MOSI and MISO signals are shared by all devices.

Figure 1: Example of Multiple SPI Slaves

Following are details about the SPI signals. When the Aardvark host adapter SS  signal is configured to active low, and the Aardvark writes to the slave device, the following transactions occur:

1. The SS signal goes from 1 to 0.
2. A few bytes are sent in the MOSI signal
3. The SS signal goes from 0 to 1.

Between the bytes there is a delay, as shown in the figures below. For additional information about MOSI (master output slave input) signals, please refer to section 2.4 of the Aardvark Adapter User Manual.

Figure 2: SPI Waveform

•   t₁: time from the assertion of SS to the first clock cycle
•   t₂: time for the last clock cycle and the desertion of SS
•   t_p: one clock period

Figure 2: SPI Byte Waveform

•    t_d: setup time between SPI bytes
•   t_b: total byte-to-byte time

For more information, please refer to the following documents:

Aardvark Host Adapter User Manual
Aardvark Software API
API Documentation
Total Phase Products
Product Selector Guide

We hope this answers your question. If you have other questions about our host adapters or other Total Phase products, feel free to email us at sales@totalphase.com or submit a request for technical support.

We are using a Komodo^TM CAN Duo Interface and Data Center^TM Software.  We need to generate CAN Bus statistics for the following:

1. Error Rate (either % or per/time)
2. Packets / Time
3. Bus Usage % (time packets on bus / time bus free)

Can you provide us information about obtaining this information for CAN bus statistics?

Thanks for your question! Using the Komodo CAN interface with the Data Center Software, there are multiple parameters for analyzing CAN bus statistics.  Detailed information is available in section 5.1  and section 5.4 of the Data Center Software User Manual. Following are examples to obtain the CAN bus statistics data that you are looking for.

 

Figure 1: Data Center Software View of CAN Data  - Timestamps and Statistics

 

To view the number of errors and type of errors in the capture to calculate error rate, please do the following:

1. In the Navigator tab (right side of the viewer), click Bus and then select Statistics. Any errors that occur on the bus will show up in the Statistics tab in the lower right corner as shown in Figure 1 above.

For calculating Packets/Time, you can look at the packet index (a sequential count of the consecutive packets on the bus), which is located in the index column in the transaction log (left side of the view), and the packet time-stamp column is located in the transaction log (next to the index column). Refer to Figure 1 above.

To look at the bus utilization percentage, the time-stamp column can be configured to display Interval Time Stamp. To do so:

1. Hover on the index and right-click the mouse.
2. Click Timestamp Reference.
3. Select Interval Time Stamp.

The time difference  and throughput between two indexes can be viewed. To do so:

1. Hover in blue on the first index, right click on the mouse, click Timestamp Reference, and choose Set Time Reference, and click on the row from where you would like to begin measurement
2. Hover in yellow on the second index, and observe the time difference between the two indexes in Delta Time parameter in the left bottom corner of the Data Center window.  The average throughput of the bus between the two selected indices is also displayed in that area. Refer to Figure 2 below.

 

Data Center Software View of CAN Data - Delta Time

 

For additional information, please refer to the following documents:

Komodo Interface User Manual
Data Center Software User Manual
Analyze and Capture CAN Traffic Using the Komodo interface and the Data Center Software
Total Phase Products
Product Selector Guide

We hope this answers your question. If you have other questions about our Host Adapters or other Total Phase products, feel free to email us at sales@totalphase.com or submit a request for technical support.

I have an SPI device that supports continuous read/write, and its format is not standard. The size of data for this device is approximate 1Mbit. Because the format is not standard, I plan to use LabVIEW so I can modify the SPI header to match the device that will drive. I have been using the Aardvark^TM I2C/SPI Host Adapter, but for the higher data rate of this device, it looks like I need to use the Cheetah^TM SPI Host Adapter to transfer the data. My questions:

• What are the limitations of transferring large amounts of data with the Cheetah adapter?
• Do you provide support for using LabVIEW with the Cheetah adapter?

Thanks for your questions! When using the Cheetah SPI Host Adapter, the amount of SPI bytes that you can send and receive are limited by the memory size that your application is allowed to allocate. On most systems, the allocated  amount is very large; there should be more than enough memory to support your requirements.

Figure 1: Cheetah SPI Host Adapter

Yes, we do provide LabVIEW drivers for use with the Cheetah adapter and examples are provided.  SPI speeds of 0.1 MHz – 40+ MHz are supported. You can easily use these examples as a springboard for creating your own custom applications.  In addition to LabVIEW, we have additional software tools to interface with the Cheetah adapter:

• The Cheetah API Software is also used to control the adapter, and to write a custom program to achieve the user goals. The API supports multiple languages (C, Python, Visual Basic, and C#) on multiple operating systems (Windows, Linux, and Mac OS), and includes examples. We recommend using the Python bindings as it is a simple language, and a good  option for scripting.
• The Flash Center™ Software is full-featured GUI that provides tools to quickly erase, program, and verify SPI based EEPROM and flash memory chips. It has extensible XML parts library with built-in support for EEPROMs and serial flash chips from major manufacturers. You can select and then modify an XML file to match the requirements of a custom chip or a device that is not yet supported. The Flash Center software is regularly updated, continuously supporting more SPI devices.
• The Cheetah GUI Software provides full access to all Cheetah adapter functionality, and eliminates the need to write custom software to control the adapter.

I'm working on a project where I need to continuously capture data - I'll be running the system overnight with the Beagle^TM USB 480 Protocol Analyzer. My questions:

• How much data can the Beagle USB protocol analyzer capture?
• Running the system overnight, will all data be captured?
• What do I need to set up or configure to do this?

Thanks for your question! The Beagle USB 480 analyzer contains a 64 MB on-board buffer, which serves two purposes:

1. Buffer large data flows during real-time capture if the analysis computer cannot stream the data off the Beagle analyzer fast enough.
2. Provide a delay for time to download and store all of the captured data.

In addition, to save memory space, you can also use the Data Center^TM Software and configure the capture settings: "Capture Settings - General and Capture Settings - General features - Circular Buffer enable" and "Settings - General and Capture Settings - USB features". For information, please refer to Data Center manual, section 4.14 and section 6.2, respectively. Following is a summary of the data capture options:

Figure 1: Data Center Software - Capture and Circular Settings

Today's article is based on a new Knowledge Base article, Sending I2C Messages Between Two Aardvark adapters Using Aardvark LabVIEW

The Aardvark^™ I2C/SPI Host Adapter is often used with LabVIEW to transfer I2C data. The Aardvark LabVIEW Driver supports the Windows operating system and includes examples. You can use the Aardvark LabVIEW Driver to control the Aardvark adapter, as well as write a custom program for specific requirements. For information about API Software, which is also used to write custom software, please refer to section 5 of the Aardvark Adapter Use Manual.  Following are instructions to install the Aardvark LabVIEW driver and then run two examples that use Aardvark LabVIEW drivers (connect and i2c):

• connect example - Indicates if the I2C/SPI/GPIO functions are available, and displays the port number, Aardvark handle, Serial Number, Hardware version, and Firmware version for the connected Aardvark adapters.
• spi example - Reads and writes I2C data between two Aardvark adapters. In this example, one Aardvark adapter is the I2C master and the other Aardvark adapter is the I2C slave.

Aardvark LabVIEW Driver Installation Guidelines:

1. Download and run the latest version of the Total Phase USB Drivers Installer.
2. Download and install the latest version of Aardvark LabVIEW Driver following the README file in the driver package.
   • Be sure to place the aardvark.dll into a directory that is listed in the system search path. The Windows system32 directory (on 32-bit Windows) is a good location for the aardvark.dll.
3. Connect the two Aardvark adapters to the computer via the USB connector.
4. Connect the two Aardvark adapters to each other via the I2C/SPI connector.
5. Install 32-bit LabVIEW for Windows from the LabVIEW website.
   • Be sure to use 32-bit LabVIEW;  currently the Aardvark LabVIEW Driver is only provided in a 32-bit package.
6. Launch Aardvark LabVIEW Driver by clicking on the icon …/aardvark-labview-v5.03/aardvark/aardvark.llb.
7. Run the original connect Aardvark LabVIEW Driver example as provided in the Aardvark LabVIEW Driver package. To do so:
   1. Go to the Aardvark Example Connect.vi window.
   2. Click Operate → Run.
   3. Verify that the computer detects the first Aardvark adapter, and that the Aardvark parameters are correct including: Aardvark Handle, Aardvark Port; Aardvark Serial Number String, Hardware Version String, and Firmware Version String. Refer to Figure 1 below.

Figure 1: Setting up Drivers for the Aardvark Host Adapter

 

Instructions to send I2C data between two Aardvark adapters with the Aardvark LabVIEW Driver SPI:

1. Go to the Aardvark LabVIEW Driver Example I2C.vi window.
2. Click Operate → Run.
3. Verify that the Aardvark parameters are correct including: Aardvark Handle 1, Aardvark Handle 2, Message received by master, and Message received by slave. Refer to Figure 2 below.

 

Fig 2: Sending I2C Data between Aardvark Host Adapters

Note: similar steps can be used for transferring I2C data between Aardvark adapter and another I2C device.

For more information, please refer to the following documents:

Aardvark Adapter User Manual
Aardvark I2C/SPI Host Adapter Quick Start Guide
LabVIEW Drivers for Aardvark
Sending I2C Messages Between Two Aardvark adapters Using Aardvark LabVIEW
Total Phase Products
Product Selector Guide

We hope this answers your question. If you have other questions about our host adapters or other Total Phase products, feel free to email us at sales@totalphase.com or submit a request for technical support.