FS4120 USB 2.0 Analysis Probe

Q: Can I do timing analysis with the FS4120?

A. The Low Speed/Full Speed section of the FS4120 allows the user to look at the serial bit stream with an Agilent timing analyzer to make relative timing measurements. The Full Speed/High Speed section does not have this feature, largely because the FPGA we use is not fast enough at the 480 MB/s speed to give us the information we need to do timing analysis.

However, we do have extensive capability in using an oscilloscope to do timing measurements. There are high speed oscilloscope connectors on our product. The FS4120 also has an oscilloscope trigger output and a switch where the user can select different types of PID's, for instance, to trigger the oscilloscope. We have designed the FS4120 so that it will serve as an all inclusive tool for almost all of the types of measurements that the USB designer will need.

Q: What is the minimum oscilloscope requirement to do testing for USB1.1 and 2.0 with the FS4120?

A. The scope must be capable of sampling a 12Mb/s data rate. It must be capable of storing a minimum of 2.5us; this is the amount of time required for a reset.

Q: Can I test SE0 and Reset with the FS4120?

A. SE0 is a signal level, a single ended 0 signal. If a SE0 occurs for a specified amount of time, then that is signaling a reset. A reset in USB 1.1 is defined as a SE0 state for >= 2.5us. The FS4120 can detect resets; we have symbols set up in our configuration files to help the user configure the analyzer to trigger on a reset.SE0 is also used to identify an EOP; in USB 1.1 an SE0 occurring for about 2 bit times followed by a J state for 1 bit time indicates an EOP.

Q. We have a Agilent 1650A logic analyzer. Can we use your USB analysis probe with it?

A. Sorry, we don't support the Agilent 16510A/B or 1650A/B because we have signals on channel 16. We suggest you contact Agilent about upgrading to a more recent machine.

Q. We have a 1670A logic analyzer. Can we use your USB analysis probe with it?

A. Yes and no. The FS4120 has two sections, a LS/FS section and a FS/HS section. The 1670 is rated at a maximum of 150 MHz and is not fast enough to analyze HS signals. So, you can use it on the LS/FS section of the FS4120, but you cannot use it on the FS/HS section.

Q. We have purchased your USB Analyzer for our use. We want to know if there is a way to view the USB data that we saved on the Agilent Logic Analyzer on a PC (using Windows or DOS)?

A. If you are using the 16600, 16700 or 16702A mainframes or the 16505 prototype analyzer you can use the FILE OUT tool to put the data in ASCII format to a file, then transfer that file to a PC. You can also use the WEB enabled feature on these mainframes to open the data in an EXCEL spread sheet format. If you are using the older frames or a portable you can save the LISTING to disk (floppy) and then transfer it to a PC. Refer to your mainframe manual's or on-line HELP for more info.

Q. Exactly what does the 10 position switch on the side of the FS4120 do?

Switch Function

• 0Trigger output on any error
• 1Trigger output on IN PID's
• 2 Trigger output on OUT PID's
• 3Trigger output on DATA PID's
• 4Trigger output on SOF PID's
• 5 Trigger output on TOKEN PID's
• 6 Trigger output on SPLIT PID's
• 7Trigger output on any error, Full Speed Locked
• 8Trigger output on any error, High Speed Locked
• 9Test mode - sends a walking 1 pattern to logic analyzer

This switch is used only for the FS/HS section of the FS4120. Additional information is in the User's Manual.

Q. How do I find out what are the latest versions of Agilent logic analyzer operating software?

A. Contact your nearest Agilent Call Center.

Q. How do I know which Agilent logic analyzer is best for my needs?

A. Click here.

Have a question you don't see answered? Contact Technical Support for a prompt answer.