USB2517 Datasheet, PDF (10/58 Pages) SMSC Corporation – USB 2.0 Hi-Speed Hub Controller

USB2517/USB2517I
5.0 PIN DESCRIPTIONS AND BUFFER TYPE 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 inac-
tive.
TABLE 5-1: USB2517/USB2517I PIN DESCRIPTIONS
Symbol
64 QFN Buffer Type
Description
USBUP_DP
USBUP_DM
VBUS_DET
Upstream USB Interfaces
59
IO-U USB Bus Data
58
These pins connect to the upstream USB bus data signals (Host
port, or upstream hub).
44
I/O12 Detect Upstream VBUS Power
Detects state of Upstream VBUS power. The MCHP 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/
56
PRT_DIS_P[7:1]
54
12
9
&
7
4
2
USBDN[7:1]_DM/
55
PRT_DIS_M[7:1]
53
11
8
6
3
1
PRTPWR[7:1]
36
39
30
20
23
26
29
IO-U
Hi-Speed USB Data & Port Disable Strap Option
USBDN_DP[7:1] / USBDN_DM[7:1]: These pins connect to the
downstream USB peripheral devices attached to the hub’s port.
Downstream Port Disable Strap option:
PRT_DIS_P[7:1] / PRT_DIS_M[7:1]: If the strap is enabled by
package and configuration settings (see Table 5-2), this pin will be
sampled at RESET_N negation to determine if the port is disabled.
To disable, pull up with 10K resistor to 3.3V.
O12 USB Power Enable
Enables power to USB peripheral devices downstream.
Note: The hub supports active high power controllers only!
DS00001598B-page 10
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