Specifications - FS4120 Universal Serial Bus (USB2.0) Analysis Probe

Description of the FS4120 USB Analysis Probe
The FS4120 USB analysis probe provides a quick, reliable electrical and mechanical interface between the USB bus and an Agilent logic analyzer. USB data is displayed on the logic analyzer in several levels of abstraction.

A variety of test jacks and connectors supply rapid access for signal integrity and current measurements using oscilloscopes and DVMs

LEDs give the user immediate visual identification when USB traffic is occurring, IN-NAK polling is taking place, SOF PIDs are suppressed, and even when a LS device is illegally connected to an FS/HS port.

State Analysis Mode
All software is included with the FS4120 and contains the USB Protocol transaction decode and complete configuration files for all supported Agilent logic analyzers.

The USB data is color coded and organized in an easy-to-read protocol-level display. Three display modes are provided; compressed, expanded, and raw. Compressed Data Display shows a high level protocol view. Expanded Data Display shows the high level protocol and includes all of the detailed data states that are used to create the compressed protocol view. Raw Data Display presents an event-by-event listing of the data. In this mode the data is displayed as HEX, ASCII, or binary.

The FS4120 gives the user complete control over viewing the data.

The FS4120 supplies a variety of tools that simplify data capture, storage qualification and triggering. For example, any USB resets are automatically detected. Triggering, store qualification and performance monitoring of specific end point addresses is made easy because the address and end point specified in the token packet are held until the transfer is complete.

For state analysis the Agilent logic analyzer only requires 2 pods (34 channels). To analyze a second USB device, using the same FS4120, two additional logic analyzer pods are required.

Timing Analysis Mode
Event timing analysis generates a 4 nsec resolution time stamp, showing the user the relative time between bus events. This capability exists for all speeds, LS, FS, and HS.

When using only the FS/LS (USB 1.1) port of the FS4120 the logic analyzer can be used in asynchronous timing mode providing a 500 psec accurate timing waveform view of the USB data.

Dual-channel Operation
The FS4120 has two independent USB channels. This gives the user the ability to simultaneously test two separate USB data paths, using only one FS4120 USB analysis probe. For example, a user could test both the upstream and downstream data from a hub.

Power Requirement
Power for the FS4120 is supplied by the Agilent logic analyzer. The analysis probe does not require any power from the USB bus or an external power supply.

Cross-Domain Analysis
Use a single Agilent 16700 series logic analyzer to simultaneously capture data from multiple buses. The user can create a custom measurement system with cross-domain triggering between different types of buses and display the time-correlated data on a single screen, with common markers.

For example, use the FS4120 to monitor the USB bus, and then use another analysis probe to monitor a different bus. FuturePlus Systems has analysis probes for the DDR, PCI-X, PCI, SCSI, Rambus, and a wide variety of other buses.

Oscilloscope Connections
SMA connectors are included for quick access to signal integrity measurements, without the use of a separate breakout board. Quickly access D+, D-, Clock and other signals.

To assist the hardware engineer in the debug process a Trigger Out (TRIG OUT) SMA connector is provided. This supplies 8 user selectable triggers that can be used to externally trigger an oscilloscope. The triggers indicate when an IN, OUT, SOF, TOKEN, SPLIT, DATA, RX_ACT, or ERR PID has occurred.

Indicators

• Connected Indicator - The Connected LED indicates that the logic analyzer power is connected to the FS4120.
• Ready Indicator - The FS/LS and the HS/FS Ready LEDs show when the connected channel is ready for operation. The HS/FS Ready LED blinks when a LS device is plugged in to the HS/FS port.
• USB Busy Indicator - The USB Busy LED illuminates when the USB Analysis Probe is actively detecting packets being sent from a USB device.
• Low Speed Indicator - The USB Low Speed LED illuminates when the low speed switch is set and the FS/LS channel is operating in LS mode only.
• IN/NAK SUP Indicator - This two-color indicator glows green when the IN/NAK suppression is enabled. When an IN PID is immediately followed by a NAK PID, the indicator flashes red to indicate that these two PIDs were not sent to the logic analyzer. In an extended polling sequence where many of these combinations are suppressed, the LED color changes to orange.
• SOF SUP Indicator - This two-color indicator is green when SOF suppression is enabled. This LED flashes red when an SOF is transmitted. In an extended polling sequence where multiple SOFs are suppressed, the LED color changes to orange.

Front Panel Switches and Connectors

• Current Range Switch - The full-scale current range is switch selectable for 1 Amp/volt, 100 mA/volt, and 1 ma/volt.
• Internal (Int.) Sense Connectors - These jacks allow current sense measurements across the selected internal current sense resistor using an oscilloscope or DVM.
• External (Ext.) Sense Connectors - These jacks provide an accurate way to measure inrush current by using a wire loop and a high speed current probe. An external power supply can be connected to these jacks and used to power a USB device.

Power Required
Electrical power for the FS4120 circuitry is drawn from the logic analyzer, not the USB bus. An external power connector is included to provide power to non-self powered devices.

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