gl850 ETC-unknow, gl850 Datasheet - Page 18

• Manufacturer Part Number: gl850
• Description: Usb 2.0 4-port Hub Controller
• Manufacturer: ETC-unknow

5.1.11.2 Connected to USB2.0 Host/Hub
5.1.12 DSPORT logic
5.1.13 DSPORT Transceiver
©2000-2003 Genesys Logic Inc.—All rights reserved.
If an USB2.0 hub is connected to an USB2.0 host/hub, it will operate in USB2.0 mode. The upstream port
signaling is in high speed with bandwidth of 480 Mbps under this environment. The traffic channel will
then be routed to the REPEATER when the device connected to the downstream port is signaling also in
high speed. On the other hand, the traffic channel will then be routed to TT when the device connected to
the downstream port is signaling in full/low speed.
DSPORT (downstream port) logic implements the control logic defined in section 11.5 of USB specification
Revision 2.0. It mainly manipulates the state machine, the connection/disconnection detection, over current
detection and power enable control, and the status LED control of the downstream port. Besides, it also
output the control signals to the DSPORT transceiver.
DSPORT transceiver is the analog circuit that supports high-speed, full-speed, and low-speed electrical
characteristics defined in chapter 7 of USB specification Revision 2.0. In addition, each DSPORT
transceiver accurately controls its own squelch level to detect the detachment and attachment of devices.
HS vs. HS:
Traffic channel is
routed to REPEATER
DSPORT operating
in HS signaling
Figure 5.2 - Operating in USB2.0 scheme
REPEATER
USB2.0 HOST/HUB
GL850 USB 2.0 4-Port HUB Controller
TT
USPORToperating
in HS signaling
DSPORT operating
in FS/LS signaling
HS vs. FS/LS:
Traffic channel
is routed to TT
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