SMSC USB2502 - Manual (Page 11)

2-Port USB 2.0 Hub Controller
Datasheet
SMSC USB2502 11 Revision 2.3 (08-27-07)
DATASHEET
Chapter 4 2-Port Hub Block Diagram
Figure 4.1 2-Port Block Diagram
Table 4.1 2-Port Hub Pin Descriptions
NAME SYMBOL TYPE FUNCTION
UPSTREAM USB 2.0 INTERFACE
USB Bus Data USBDN0
USBDP0 IO-U These pins connect to the upstream USB bus data signals.
Detect Upstream
VBUS Power
VBUS_DET I/O8 Detects state of Upstream VBUS power. The SMSC Hub
monitors VBUS_DET to determine when to assert the
internal D+ pull-up resistor (signalling a connect event).
When designing a detachable hub, this pin must be
connected to the VBUS power pin of the USB port that is
upstream of the hub. (Use of a weak pull-down resistor is
recommended.)
For self-powered applications with a permanently attached
host, this pin must be pulled-up to either 3.3V or 5.0V
(typically VDD33).
8SVWUHDP
V
BUS
3.3V
Upstream
PHY
Upstream
USB Data
Repeater Controller SIE
Serial
Interface
PLL
24 MHz
Crystal
To EEPROM or
SMBus Master
Routing Logic
SCK SD
Port
Controller
Downstream PHY #1
OC Sense
Switch Driver
LED Driver
Strapping Options
Downstream PHY #2
Downstream
USB Data
OC
Sense
Switch/LED
Driver/optís
Downstream
USB Data
Bus-Power
'HWHFW
1.8V
Transaction Translator
1.8V Reg