USB2513B-AEZC View Datasheet(PDF) - SMSC -> Microchip
Part Name
Description
MFG CO.
'USB2513B-AEZC' PDF : 63 Pages View PDF
USB 2.0 Hi-Speed Hub Controller
Datasheet
3.3.1 Configuring the Strap Pins
If a pin's strap function is enabled thru the hub configuration selection, (Table 5.1: Initial
Interface/Configuration Options on page 26) the strap pins must be pulled either high or low using the
values provided in Table 3.4. Each strap option is dependent on the pin’s buffer type, as outlined in
the sections that follow.
Table 3.4 Strap Option Summary
STRAP OPTION
Non-Removable
Internal Pull-Down
LED
RESISTOR VALUE BUFFER TYPE
NOTES
47 - 100 kΩ
10 kΩ
47 - 100 kΩ
I/O
Only applicable to port power pins
IPD
Contains a built-in resistor
I/O
3.3.1.1
Non-Removable
If a strap pin’s buffer type is I/O, an external pull-up or pull-down must be implemented as shown in
Figure 3.4. Use Strap High to set the strap option to 1 and Stap Low to set the strap option to 0. When
implementing the Strap Low option, no additional components are needed (i.e., the internal pull-down
provides the resistor)
+V
R kΩ
I/O Strap Pin
HUB
Strap High I/O Strap Pin
HUB
Strap Low
R kΩ
GND
3.3.1.2
Figure 3.4 Non-Removable Pin Strap Example
Internal Pull-Down (IPD)
If a strap pin’s buffer type is IPD (pins BC_EN[x:1]), one of the two hardware configurations outlined
below must be implemented. Use the Strap High configuration to set the strap option value to 1 and
Strap Low to set the strap option value to 0.
+V
R kΩ
IPD Strap Pin
Strap High IPD Strap Pin
Strap Low
HUB
VSS
HUB
VSS
Figure 3.5 Pin Strap Option with IPD Pin Example
Revision 2.2 (02-17-12)
22
DATASHEET
SMSC USB251xB/xBi
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