gt3200 SMC Corporation, gt3200 Datasheet - Page 31

• Manufacturer Part Number: gt3200
• Description: Usb2.0 Phy Ic
• Manufacturer: SMC Corporation

USB2.0 PHY IC
SMSC GT3200, SMSC USB3250
7.6
7.7
7.8
7.9
RXDATA[7:0]
RXACTIVE
RXERROR
RXVALID
DP/DM
CLK60
The receivers connect directly to the USB cable. The block contains a separate differential receiver
for HS and FS mode. Depending on the mode, the selected receiver provides the serial data stream
through the mulitplexer to the RX Logic block. The FS mode section of the FS/HS RX block also
consists of a single-ended receiver on each of the data lines to determine the correct FS LINESTATE.
For HS mode support, the FS/HS RX block contains a squelch circuit to insure that noise is never
interpreted as data.
The transmitters connect directly to the USB cable. The block contains a separate differential FS and
HS transmitter which receive encoded, bitstuffed, serialized data from the TX Logic block and transmit
it on the USB cable. The FS/HS TX block also contains circuitry that either enables or disables the
pull-up resistor on the D+ line.
This block consists of an internal bandgap reference circuit used for generating the driver current and
the biasing of the analog circuits. This block requires an external precision resistor (12k
the RBIAS pin to analog ground).
This is the block that receives and distributes all the power for the transceiver. This block is also
responsible for handling ESD protection.
FS/HS RX
FS/HS TX
Biasing
Power Control
Figure 7.12 Receive Timing for Data Packet with CRC-16 (8-bit mode)
SYNC
PID
DATA
DATASHEET
PID
DATA
26
DATA
CRC-16 Computation
DATA
DATA
DATA
DATA
CRC
DATA
CRC
CRC
Revision 1.3 (10-05-04)
EOP
CRC
+/- 1% from