EVB-USB3320 USB Transceiver Evaluation Board User Manual
Revision 1.0 (02-09-10)
4
SMSC EVB-USB3320
USER MANUAL
2.8
ULPI Signal Test Points
Probe points at location J2, provide access to all ULPI signals. Install the Tektronix logic analyzer probe
retention kit at J2 to probe these signals. Ordering information for the retention kit is provided in the
bill of materials.
2.9
Converting the EVB to an OTG System
“Out of the box”, the EVB-USB3320 is delivered as a USB Device system. To convert it to be a USB
OTG development board, the following modifications must be made:
1. Install R13 (zero ohm resistor). This connects the VBUS 5V switch to the VBUS signal.
2. Remove R23. This is the R
VBUS
value required for a USB Device.
3. Install R10 (1.0K, 1W resistor). This is the R
VBUS
value required for a USB OTG Device.
Since the USB3320 is designed to accommodate up to 30V on VBUS, R10 is rated at 1W to
accommodate this entire voltage range. Refer to the USB3320 datasheet for more information on sizing
this resistor.
2.10
Converting the EVB to a Host System
“Out of the box”, the EVB-USB3320 is delivered as a USB Device System. To convert it to be a USB
Host development board, the following modifications must be made:
1. Install R13 (zero ohm resistor). This connects the VBUS 5V switch to the VBUS signal.
2. Install C20 (150uF capacitor). This increases the value of C
VBUS
to be USB 2.0 Host compliant.
2.11
Converting the EVB to Support ULPI Clock Input Mode
“Out of the box”, the EVB-USB3320 uses a crystal (Y1) as the clock reference, and is configured for
ULPI Clock Output Mode where CLKOUT sources a 60MHz clock. To convert the EVB to support ULPI
Clock Input Mode, the following changes must be made:
1. Install R12 (zero ohm resistor). This shorts CLKOUT to VDD18.
2. Install R3 (zero ohm resistor). This shorts REFCLK to the System Clock pin on the T&MT
connector.
3. Confirm that R4 is not populated.
4. Remove the following components to remove the crystal circuit: Y1, R17, C23
Refer to the USB3320 datasheet for more information on ULPI Clock Input Mode.
2.12
T&MT Pin Description
The T&MT signal names, pin number and function are described in Table 43 and Table 44 of the ULPI
Specification rev 1.1.
The EVB-USB3320 fully implements a ULPI compliant interface to the T&MT connector, including
support for ULPI Clock Input Mode. This EVB supports a 1.8V ULPI I/O voltage. All signals are
described in
