Tektronix TDS5032, Manual

Page: 212 / 248

Measurement Algorithms
Packet Parameter
The algorithm calculates the SYNC field length, EOP length, and the Inter-
Packet gap. The acceptable range of EOP for all transmitted packets (except
SOFs) must be between 7.5 and 8.5 bits. The packet parameter algorithm
calculates and verifies the EOP depending on this range.
The acceptable range of inter-packet gap should be between 88 bits to 192 bits.
The SYNC field for all transmitted packets is calculated by counting the bits to
check for 32-bit SYNC field. The inter-packet delay and SYNC status is
calculated between the respective EOP indexes of the packets. The EOP width in
time is calculated by dividing the EOP width by the signaling rate of 480 Mbps.
Oscilloscope setup details
The application sets the oscilloscope automatically to the following values:
Horizontal Scale: 400 ns
Record Length: 50 K
Vertical Scale: 200 mV
Trigger Type Pulse Width
Trigger Hold Off: 5 s
198 TDSUSB2 Universal Serial Bus Measurement Package