SMSC USB2502 Chapter 4 2-PortHub Block Diagram

2-Port USB 2.0 Hub Controller

Datasheet

Chapter 4 2-Port Hub Block Diagram

8SVWUHDP	Upstream			24 MHz	To EEPROM or
VBUS	USB Data			Crystal		SMBus Master
		3.3V			1.8V				SD SCK
				PLL				Serial
Bus-Power	Upstream						Interface
'HWHFW	PHY		1.8V Reg
				SIE			Controller
	Repeater
		Transaction Translator						Port
							Controller

Routing Logic

OC Sense

Switch Driver

Downstream PHY #1Downstream PHY #2

LED Driver

Strapping Options

	Downstream		OC	Switch/LED	Downstream
	USB Data		Sense	Driver/optís	USB Data
		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		IO-U	These pins connect to the upstream USB bus data signals.
	USBDP0
Detect Upstream	VBUS_DET		I/O8	Detects state of Upstream VBUS power. The SMSC Hub
VBUS Power				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).

SMSC USB2502	11	Revision 2.3 (08-27-07)
	DATASHEET