USB3320C-EZK-TR Standard Microsystems (SMSC), USB3320C-EZK-TR Datasheet - Page 34

• Manufacturer Part Number: USB3320C-EZK-TR
• Manufacturer: Standard Microsystems (SMSC)

Specifications of USB3320C-EZK-TR

• Number Of Transceivers: 1
• Esd Protection: YeskV
• Operating Supply Voltage (typ): Not RequiredV
• Operating Temperature Classification: Industrial
• Operating Supply Voltage (max): Not RequiredV
• Operating Supply Voltage (min): Not RequiredV
• Pin Count: 32
• Mounting: Surface Mount
• Operating Temperature (max): 85C
• Operating Temperature (min): -40C
• Lead Free Status / RoHS Status: Compliant

Revision 1.0 (07-14-09)
5.6.1.1
5.6.1.2
USB OTG Operation
The USB3320 can detect ID grounded and ID floating to determine if an A or B cable has been
inserted. The A plug will ground the ID pin while the B plug will float the ID pin. These are the only
two valid states allowed in the OTG Protocol.
To monitor the status of the ID pin, the Link activates the IdPullup bit in the
50mS and then reads the status of the IdGnd bit in the
been inserted the IdGnd bit will read 0. If a B cable is inserted, the ID pin is floating and the IdGnd bit
will read 1.
The USB3320 provides an integrated weak pull-up resistor on the ID pin, R
to keep the ID pin in a known state when the IdPullup bit is disabled and the ID pin is floated. In
addition to keeping the ID pin in a known state, it enables the USB3320 to generate an interrupt to
inform the link when a cable with a resistor to ground has been attached to the ID pin. The weak pull-
up is small enough that the largest valid Rid resistor pulls the ID pin low and causes the IdGnd
comparator to go low.
After the link has detected an ID pin state change, the RID converter can be used to determine the
resistor value as described in
Measuring ID Resistance to Ground
The Link can used the integrated resistance measurement capabilities to determine the value of an ID
resistance to ground.
detect.
To USB Con.
VDD33
ID
~ ~
~ ~
Figure 5.10 USB3320 ID Resistor Detection Circuitry
Table 5.4
IdGndDrv
Section
lists the valid values of resistance, to ground, that the USB3320 can
DATASHEET
IdPullup
5.6.1.2.
V
V
OTG Module
ref
34
ref
IdFloat
IdGnd
Rid ADC
USB Interrupt Status
en
en
Highly Integrated Full Featured Hi-Speed USB 2.0 ULPI Transceiver
IdFloatRise or
IdGnd Rise or
IdGnd Fall
IdFloatFall
RidValue
IdFloat
IdGnd
IDW
OTG Control
register. If an A cable has
. This resistor is present
SMSC USB3320
register, waits
Datasheet