Datasheet
USB 2.0 Hi-Speed 7-Port Hub Controller
Datasheet
SMSC USB2517 11 Revision 2.8 (09-17-12)
DATASHEET
Chapter 5 Pin Descriptions
5.1 PIN Descriptions
This section provides a detailed description of each signal. The signals are arranged in functional groups according
to their associated interface.
The “N” symbol in the signal name indicates that the active, or asserted, state occurs when the signal is at a low
voltage level. When “N” is not present before the signal name, the signal is asserted when at the high voltage level.
The terms assertion and negation are used exclusively. This is done to avoid confusion when working with a mixture
of “active low” and “active high” signals. The term assert, or assertion, indicates that a signal is active, independent
of whether that level is represented by a high or low voltage. The term negate, or negation, indicates that a signal
is inactive.
Table 5.1 USB2517 Pin Descriptions
SYMBOL 64 QFN
BUFFER
TYPE DESCRIPTION
UPSTREAM USB INTERFACES
USBUP_DP
USBUP_DM
59
58
IO-U USB Bus Data
These pins connect to the upstream USB bus data signals (Host
port, or upstream hub).
VBUS_DET
44 I/O12 Detect Upstream VBUS Power
Detects state of Upstream VBUS power. The SMSC Hub monitors
VBUS_DET to determine when to assert the internal D+ pull-up
resistor (signaling 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 from the
hub.
For self-powered applications with a permanently attached host,
this pin must be connected to 3.3V or 5.0V (typically VDD33).
DOWNSTREAM 7-PORT USB 2.0 INTERFACES
USBDN[7:1]_DP/
PRT_DIS_P[7:1]
&
USBDN[7:1]_DM/
PRT_DIS_M[7:1]
2
4
7
9
12
54
56
IO-U Hi-Speed USB Data & Port Disable Strap Option
USBDN_DP[7:1] / PRT_DIS_P[7:1]: These pins connect to the
downstream USB peripheral devices attached to the hub’s port.
To disable, pull up with 10K resistor to 3.3V.
1
3
6
8
11
53
55
Downstream Port Disable Strap option:
USBDN_DM[7:1] / PRT_DIS_M[7:1]: If this strap is enabled by
package and configuration settings (see Tab l e 5 . 2 ), this pin will be
sampled at RESET_N negation to determine if the port is
disabled.
PRTPWR[7:1] 36
39
30
20
23
26
29
O12 USB Power Enable
Enables power to USB peripheral devices downstream.
Note: The hub supports active high power controllers only!