Teledyne LeCroy HPT - Users Manual - Manual (Page 8)

CATC HPT User’s Manual Version 2.27
Page 6
3. reset the HPT test device to put it in a default condition;
4. enable the first USB port for communication with the HPT device; and
5. send a sequence of USB messages (as described below) to the HPT test device.
The application then issues commands to the HPT test device to execute a series of four (or two,
if only one port is being tested) Port Test Sequences. If two ports are connected, the tests are
performed in the following order:
full-speed test sequence at the port connected to “CH 1”
low-speed test sequence at the port connected to “CH 1”
full-speed test sequence at the port connected to “CH 2”
low-speed test sequence at the port connected to “CH 2”
Prior to conducting each test sequence, the program checks for the correct Connection Status and
Connection Change Status for both USB ports.
5.2 Port Test Sequence
As a principal element of the host production test, the CATC HPT software sends a specific USB
message sequence to the HPT test device. For each test sequence the following items are verified:
•
data returned properly by the device (successful IN/OUT transfers);
•
correct status for each transfer;
•
proper USB Interrupt functionality (interrupt on completion for each transfer); and
•
absence of host controller process errors, host system errors, and USB protocol errors
The test sequence includes the USB messages enumerated below. The specific USB packets
involved are illustrated using data captured on the bus by a CATC Detective USB Bus &
Protocol Analyzer during actual HPT tests.
5.2.1 Set Address
The first control transfer issued by the HPT application program sets the HPT test device address
to 1. All subsequent USB transfers use this address.