Datasheet

2-Port USB 2.0 Hi-Speed Hub Controller

Datasheet

Revision 1.3 (12-27-11) 12 SMSC USB2412

DATASHEET

2.4 Buffer Type Descriptions

2.5 Strap Option Pins

The NON_REM[1:0] strap option pins can be enabled using the internal default configuration. The

driver type of each strap pin is I/O (no internal pull-up or pull-down for the input function). Figure 2.2

shows an example of Strap High and Strap Low configurations, where Strap High sets the strap option

to a 1 and Strap Low sets the strap option value to 0. To use an external LED indicator, the options

outlined in Figure 2.3 should be implemented.

Figure 2.2 Non-Removable Pin Strap Example

29 ePAD Ground Pad/ePad: this pin must be connected to VSS for the device

and must be tied to ground with multiple vias

5 NC No Connect: no signal or trace should be routed or attached to these

pins.

Table 2.3 Buffer Type Descriptions

BUFFER DESCRIPTION

I/O Input/Output

IPD Input with internal weak pull-down resistor

IPU Input with internal weak pull-up resistor

IS Input with Schmitt trigger

I/O12 Input/Output buffer with 12 mA sink and 12 mA source

ICLKx XTAL clock input

OCLKx XTAL clock output

I-R RBIAS

I/O-U Analog Input/Output defined in USB specification

Table 2.2 USB2412 Pin Descriptions (continued)

# SYMBOL

BUFFER

TYPE DESCRIPTION

HUB

Strap Pin

Primary Function/

Strap High

HUB

Strap Pin

Primary Function/

Strap Low

GND

50 kΩ