20H04 Datasheet, PDF (9/38 Pages) SMSC Corporation – 4-PORT USB2.0 HUB CONTROLLER

4-Port USB2.0 Controller
Datasheet
1.2
OEM Selectable Features
The 4-Port Hub supports several OEM selectable features:
ƒ Operation as a bus-powered, self-powered or dynamic-powered hub. (When configured for dynamic
operation, the controller automatically switches to bus-powered mode if a local power source is
unavailable).
ƒ Configure downstream facing port power switching on an individual or ganged basis.
ƒ Configure downstream facing port over-current sensing on an individual or ganged basis.
ƒ Enable downstream facing port LED indicators.
ƒ Select multiple or single transaction translator mode.
ƒ Select whether the hub is part of a compound device (when any downstream facing port is
permanently hardwired to a USB peripheral device, the hub is part of a compound device).
ƒ Select the presence of a permanently hardwired USB peripheral device on a port by port basis.
ƒ Enable downstream facing ports a port by port basis.
ƒ Enable EOP generation of EOF1 when operating in full-speed mode, as described in Section 11.3.1 of
the USB2.0 Specification.
ƒ Enable USB On-The-Go Session Request Protocol (SRP) support.
ƒ Configure the delay time for filtering the over-current sense inputs.
ƒ Configure the delay time until port power is good after the SetPortPower command is received.
ƒ Indicate the maximum current that the 4-port hub consumes from an upstream port.
ƒ Indicate the maximum current required for the hub controller.
1.3
Pin Selectable Options to the Default Configuration
The USB20H04 includes a default configuration for those applications where an external EEPROM or
SMBus device is not available to provide the configuration. This configuration may be adequate in some
applications. A pin selectable feature supports configuration as either a bus-powered hub or a
self-powered hub determined by the logic level of the SELF_PWR pin following reset.
SMSC USB20H04
Page 9
DATASHEET
Revision 1.63 (10-14-04)