gl850 ETC-unknow, gl850 Datasheet - Page 17

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

5.1.9 REPEATER
5.1.10 TT (Transaction Translator)
5.1.11 REPEATER/TT routing logic
5.1.11.1 Connected to 1.1 Host/Hub
©2000-2003 Genesys Logic Inc.—All rights reserved.
Repeater logic implements the control logic defined in section 11.4 and section 11.7 of USB specification
Revision 2.0. REPEATER controls the traffic flow when upstream port and downstream port are signaling
in the same speed. In addition, REPEATER will generate internal resume signal whenever a wakeup event
is issued under the situation that hub is globally suspended.
TT implements the control logic defined in section 11.14 ~ 11.22 of USB specification Revision 2.0. TT
basically handles the unbalanced traffic speed between the USPORT (operating in HS) and DSPORTS
(operating in FS/LS) of hub. GL850 adopts the single TT architecture to provide the most cost effective
solution. Single TT shares the same buffer control module for each downstream port.
REPEATER and TT are the major traffic control machines in the USB2.0 hub. Under situation that
USPORT and DSPORT are signaling in the same speed, REPEATER/TT routing logic switches the traffic
channel to the REPEATER. Under situation that USPORT is in the high speed signaling and DSPORT is in
the full/low speed signaling, REPEATER/TT routing logic switches the traffic channel to the TT.
If an USB2.0 hub is connected to the downstream port of an USB1.1 host/hub, it will operate in USB1.1
mode. For an USB1.1 hub, both upstream direction traffic and downstream direction traffic are passing
through REPEATER. That is, the REPEATER/TT routing logic will route the traffic channel to the
REPEATER.
Traffic channel
is routed to
REPEATER
Figure 5.1 - Operating in USB1.1 scheme
REPEATER
USB1.1 HOST/HUB
TT
GL850 USB 2.0 4-Port HUB Controller
DSPORT operating
in FS/LS signaling
USPORToperating
in FS signaling
Page 17