2 Hardware Specifications

2.1 Beagle USB 480 Protocol Analyzer

Connector Specification

On one side of the Beagle USB 480 monitor is a single USB-B receptacle. This is the Analysis side (Figure 18). This port connects to the analysis computer that is running the Beagle Data Center software or custom application. Furthermore, the Beagle USB 480 analyzer Analysis side must be plugged in at anytime a target device is plugged in. This is to ensure that all connections are properly powered.

The opposite side is the Capture side (Figure 19), and it contains a USB-A and USB-B receptacle. These are used to connect the target host computer to the target device. The target host computer can be the same computer as the analysis computer, although it may not be optimal under certain conditions.

The Capture side acts as a USB pass-through. In order to remain within the USB 2.0 specifications, no more than 5 meters of USB cable should be used in total between the target host computer and the target device.

The Capture side also includes a mini-DIN 9 connector which serves as a connection to the digital inputs and outputs. Its pin outs are described in Figure 20 and the cable coloring for the included cable are described in Table 5.

The top of the Beagle USB 480 Protocol Analyzer has three LED indicators as shown in Figure 21. The green LED serves as an Analysis Port connection indicator. The green LED will be illuminated when the Beagle analyzer has been correctly connected to the analysis computer and is receiving power from USB. The amber LED serves as a Target Host connection indicator. The amber LED will be illuminated when the target host computer is connected to the analyzer. Finally, the red LED is an activity LED. Its blink rate is proportional to the amount of data being sent across the monitored bus. If no data is seen on the bus, but the capture is active, the activity LED will simply remain on.

Please check all the connections if the green or the amber LED fail to illuminate after the Beagle USB 480 analyzer has been connected to the analysis computer and the target host computer.

Digital I/O

Digital inputs allow users to synchronize external logic with the analyzed USB data stream. Whenever the state of an enabled digital input changes, an event will be sent to the analysis PC. The digital input may not oscillate at a rate faster than 30 MHz. Any faster and the events may not be passed to the PC. Also, when an active data packet is on the bus, only one input event will be recorded and sent back to the analysis PC. Once the packet has completed, the latest state of the lines (if changed) will be sent back to the PC. Digital inputs are rated for 3.3 V.

Digital outputs allow users to output events to external devices, such as an oscilloscope or logic analyzer, especially to trigger the oscilloscope to capture data. Digital outputs can be set to activate on various conditions that are described more thoroughly in Section 3.3. The digital outputs are rated to 3.3 V and 10 mA.

On-board Buffer

The Beagle USB 480 analyzer contains a 64 MB on-board buffer. This buffer serves two purposes. It helps buffer large data flows during real-time capture when the analysis computer can not stream the data off the Beagle analyzer fast enough. It is also used during a delayed-download capture to store all of the captured data.

Hardware Filters

The Beagle USB 480 analyzer provides six different hardware filters. These will filter out data-less transactions in the hardware, such as IN+NAK and PING+NAK combinations. The unwanted data is thrown away, reducing the amount of captured data on the device, the amount of analysis traffic back to the analysis PC, and the processing overhead on the analysis PC. A more detailed overview of the hardware filters is available in Section 49.

Signal Specifications / Power Consumption

Speed

The Beagle USB 480 Protocol Analyzer supports capture of all wired USB speeds. The analyzer has automatic speed detection as well as manual speed locking.

ESD Protection

The Beagle analyzer has built-in electrostatic discharge protection to prevent damage to the unit from high voltage static electricity.

Power consumption

When the Beagle analyzer is connected, it consumes a maximum of approximately 2.5 mA from the capture host. This is a minimal overhead in addition to the current draw of the target device. Note that if a capture target reports itself as a 100 mA device and draws almost all of that current, the Beagle analyzer’s extra power consumption may cause the overall power consumption to be out of spec.

The Beagle analyzer consumes a maximum of approximately 180 mA.

2.2 Beagle USB 12 Protocol Analyzer

Connector Specification

On one side of the Beagle USB 12 monitor is a single USB-B receptacle. This is the Analysis side (Figure 22). This port connects to the analysis computer that is running the Beagle Data Center software.

On the opposite side is the Capture side (Figure 23), are a USB-A and USB-B receptacle. These are used to connect the target host computer to the target device. The target host computer can be the same computer as the analysis computer.

The Capture side acts as a USB pass-through. In order to remain within the USB 2.0 specifications, no more than 5 meters of USB cable should be used in total between the target host computer and the target device. The Beagle USB 12 monitor is galvanically isolated from the USB bus to ensure the signal integrity.

Please note, that on the Capture side, there is a small gap between the two receptacles. In this gap, two LED indicators are visible, a green one and an amber one, as shown in Figure 24. When the Beagle USB 12 monitor has been correctly connected to the analysis computer, the green LED will illuminate. When the Beagle USB 12 monitor is correctly connected to the target host computer, the amber LED will illuminate.

Please check all the connections if the one or both LEDs fail to illuminate after the Beagle USB 12 monitor has been connected to the analysis computer or the target host computer.

Signal Specifications / Power Consumption

Speed

The Beagle USB 12 Protocol Analyzer supports full- and low-speed capture. It does not support high-speed protocols for capture. The uplink to the analysis PC must be high-speed.

ESD protection

The Beagle analyzer has built-in electrostatic discharge protection to prevent damage to the unit from high voltage static electricity.

Power consumption

The Beagle analyzer consumes a maximum of approximately 15 mA from the capture host. This is a minimal overhead in addition to the current draw of the target device. Note that if a capture target reports itself as a 100 mA device and draws almost all of that current, the Beagle analyzer’s extra power consumption will cause the overall power consumption to be out of spec.

Furthermore, the Beagle analyzer consumes a maximum of approximately 125 mA of power from the analysis PC. However, it reports itself to the analysis PC as a low-power device. This reporting allows the Beagle analyzer to be used when its analysis port is connected to a bus-powered hub (which are only technically specified to supply 100 mA per port). Normally this extra amount of power consumption should not cause any serious problems since other ports on the hub are most likely not using their full 100 mA budget. If there are any concerns regarding the total amount of available current supply, it is advisable to plug the Beagle analyzer’s directly into the analysis PC’s USB host port or to use a self-powered hub.

2.3 Beagle I2C/SPI/MDIO Protocol Analyzer

Connector Specification

The ribbon cable connector is a standard 0.100” (2.54mm) pitch IDC type connector. This connector will mate with a standard keyed boxed header.

Alternatively, split cables are available which connects to the ribbon cable and provides individual leads for each pin with or without grabber clips.

Orientation

The ribbon cable pin order follows the standard convention. The red line indicates the first position. When looking at your Beagle analyzer in the upright position (figure 25), pin 1 is in the top left corner and pin 10 is in the bottom right corner.

If you flip your Beagle analyzer over (figure 26) such that the text on the serial number label is in the proper upright position, the pin order is as shown in the following diagram.

Order of Leads

1. SCL

2. GND

3. SDA

4. NC/+5V

5. MISO

6. NC/+5V

7. SCLK/MDC

8. MOSI/MDIO

9. SS

10. GND

Ground

GND (Pin 2):
GND (Pin 10):

It is imperative that the Beagle analyzer’s ground lead is connected to the ground of the target system. Without a common ground between the two, the signaling will be unpredictable and communication will likely be corrupted. Two ground pins are provided to ensure a secure ground path.

I2C Pins

SCL (Pin 1):

Serial Clock line – the signal used to synchronize communication between the master and the slave.

SDA (Pin 3):

Serial Data line – the bidirectional signal used to transfer data between the transmitter and the receiver.

SPI Pins

SCLK (Pin 7):

Serial Clock – control line that is driven by the master and regulates the flow of the data bits.

MOSI (Pin 8):

Master Out Slave In – this data line supplies output data from the master which is shifted into the slave.

MISO (Pin 5):

Master In Slave Out – this data line supplies the output data from the slave to the input of the master.

SS (Pin 9):

Slave Select – control line that allows slaves to be turned on and off via hardware control.

MDIO Pins

MDC (Pin 7):

Management Data Clock – control line that is driven by the STA and synchronizes the flow of the data on the MDIO line.

MDIO (Pin 8):

Management Data Input/Output – the bidirectional signal used to transfer data between the STA and the MMD.

Powering Downstream Devices

It is possible to power a downstream target, such as an I2C or SPI EEPROM with the Beagle analyzer’s power (which is provided by the analysis PC’s USB port). It is ideal if the downstream device does not consume more than 20–30 mA. The Beagle analyzer is compatible with USB hubs as well as USB host controllers. Bus-powered USB hubs are technically only rated to provide 100 mA per USB device. If the Beagle analyzer is directly plugged into a USB host controller or a self-powered USB hub, it can theoretically draw up to 500 mA total, leaving approximately 375 mA for any downstream target. However, the Beagle analyzer always reports itself to the host as a low-power device. Therefore, drawing large amounts of current from the host is not advisable.

Signal Specifications / Power Consumption

Speed

The Beagle I2C/SPI/MDIO is capable of monitoring I2C bus bit rates of up to 4 MHz, SPI bit rates of up to 24 MHz, and MDIO bit rates of up to 2.5 MHz. Both I2C and MDIO monitoring can sustain their respective maximum speeds, however SPI monitoring at the maximum bit rate may not be possible for sustained traffic. The exact limitations of SPI monitoring are dependent on the target bus conditions and the CPU of the host PC. For example, the worst-case situation is a sustained sequence of short SPI packets at the maximum bus bit rate of 24 MHz.

It is important to note that in order to properly capture I2C , SPI, or MDIO signals, the sampling rate must be set properly. For SPI or MDIO monitoring, the minimum requirement for the sampling rate is twice the bus bit rate. For I2C monitoring, the sampling rate should be 5–10 times the bus bit rate. For further details on this refer to Section 3.3.

Logic High Levels

All signal levels should be nominally 3.3 V (+/- 10%) logic high. This allows the Beagle analyzer to be used with both TTL (5 V) and CMOS logic level (3.3 V) devices. A logic high of 3.3 V will be adequate for TTL-compliant devices since such devices are ordinarily specified to accept logic high inputs above approximately 3 V.

ESD protection

The Beagle analyzer has built-in electrostatic discharge protection to prevent damage to the unit from high voltage static electricity. This adds a small amount of parasitic capacitance (approximately 15 pF) to the signal path under analysis.

Power Consumption

The Beagle analyzer consumes approximately 125 mA of power from the analysis PC. However, it reports itself to the analysis PC as a low-power device. This reporting allows the Beagle analyzer to be used when its analysis port is connected to a bus-powered hub (which are only technically specified to supply 100 mA per port). Normally this extra amount of power consumption should not cause any serious problems since other ports on the hub are most likely not using their full 100 mA budget. If there are any concerns regarding the total amount of available current supply, it is advisable to plug the Beagle analyzer’s directly into the analysis PC’s USB host port or to use a self-powered hub.

2.4 USB 2.0

All Beagle analyzers are high-speed USB 2.0 devices. They require a high-speed USB 2.0 host controller for the analysis data connection.

2.5 Temperature Specifications

The Beagle analyzers are designed to be operated at room temperature (10–35° C). The electronic components are rated for standard commercial specifications (0–70° C). However, the plastic housing, along with the ribbon and USB cables, may not withstand the higher end of this range. Any use of the Beagle analyzer outside the room temperature specification will void the hardware warranty.