GL3522-22 Datasheet

© 2014 Genesys Logic, Inc. - All rights reserved.

Page 18

GLI Confidential

4.2.13.2 Connected to USB 2.0 Host/Hub

If an USB 2.0 hub is connected to an USB 2.0 host/hub, it will operate in USB 2.0 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.

USB 2.0 Host/Hub

REPEATER

TT

USPORToperating

in HS signaling

HS vs. FS/LS:

Traffic channel

is routed to TT

HS vs. HS:

Traffic channel is

routed to REPEATER

DSPORT operating

in HS signaling

DSPORT operating

in FS/LS signaling

TT

Figure 4.3 - Operating in USB 2.0 Schemes

4.2.14 CDP Control Logic

CDP (charging downstream port) control logic implements the logic defined in USB Battery charging

specification revision 1.2. The major function of it is to control DSPORT Transceiver to make handshake

with a portable device which is compliant with USB Battery charging spec rev1.2 as well. After recognizing

charging detection each other, portable device will draw up to 1.5A from VBUS to fast charge its battery.

4.2.15 USB 3.0/USB 2.0 DSPORT Transceiver

DSPORT transceiver is the analog circuit that supports high-speed, full-speed, and low-speed electrical

characteristics. In addition, each DSPORT transceiver accurately controls its own squelch level to detect the

detachment and attachment of devices.