USB2502-AEZG Standard Microsystems (SMSC), USB2502-AEZG Datasheet - Page 32

• Manufacturer Part Number: USB2502-AEZG
• Manufacturer: Standard Microsystems (SMSC)

Specifications of USB2502-AEZG

• Lead Free Status / RoHS Status: Compliant

Revision 2.3 (08-27-07)
5.3.9.19
5.4
5.5
5.6
Default Configuration Option:
Default Strapping Options:
Reset
Reserved Registers
Unless otherwise instructed, only a ‘0’ may be written to all reserved registers or bits.
The SMSC Hub can be configured via its internal default configuration. (please see for specific details
on how to enable default configuration.
Please refer to
selected.
The SMSC Hub can be configured via a combination of internal default values and pin strap options.
Please see
default/pin-strap configuration option.
The strapping option pins only cover a limited sub-set of the configuration options. The internal default
values will be used for the bits & registers that are not controlled by a strapping option pin. Please
refer to
The Green LED pins are sampled after RESET_N negation, and the logic values are used to configure
the hub if the internal default configuration mode is selected. The implementation shown below (see
Figure
configuration, the LED functions with active low signalling, and the PAD will “sink” the current from the
external supply. When a pin is configured with a “Strap Low” configuration, the LED functions with
active high signalling, and the PAD will “source” the current to the external LED.
There are two different resets that the Hub experiences. One is a hardware reset (via the RESET_N
pin) and the second is a USB Bus Reset.
5.1) shows a recommended passive scheme. When a pin is configured with a “Strap High”
Table 5.1 on page 19
Table 4.1, "7-Port Hub Pin Descriptions"
Table 5.1 on page 19
HUB
Figure 5.1 LED Strapping Option
for the internal default values that are loaded when this option is selected.
GR2
GR1
DATASHEET
for the internal default values that are loaded when this option is
32
50K
50K
+V
for specific details on how to enable the
Strap High
Strap Low
2-Port USB 2.0 Hub Controller
SMSC USB2502
Datasheet