Datasheet
USB 2.0 Hi-Speed 7-Port Hub Controller
Datasheet
Revision 2.8 (09-17-12) 12 SMSC USB2517
DATASHEET
LED_A[7:1]_N/
PRT_SWP[7:1]
15
17
31
33
47
49
51
I/O12 Port LED Indicators & Port Swap strapping option
Indicator LED for ports 1-7. Will be active low when LED support
is enabled via EEPROM or SMBus.
If this strap is enabled by package and configuration settings (see
Ta b l e 5. 2), this pin will be sampled at RESET_N negation to
determine the electrical connection polarity of the downstream
USB Port pins (USB_DP and USB_DM).
Also, the active state of the LED will be determined as follows:
‘0’ = Port Polarity is normal, LED is active high.
‘1’ = Port Polarity (USB_DP and USB_DM) is swapped, LED is
active low.
LED_B[7:4]_N 14
16
18
32
I/O12 Enhanced Indicator Port 4-7 LED
Enhanced Indicator LED for ports 4-7. Will be active low when
LED support is enabled via EEPROM or SMBus.
LED_B3_N/
GANG_EN
34 I/O12 Enhanced Port 3 LED, Gang Power, and Over-current Strap
Option
Enhanced Indicator LED for port 3. Will be active low when LED
support is enabled via EEPROM or SMBus.
GANG_EN: Selects between Gang or Individual Port power and
Over-current sensing.
If this strap is enabled by package and configuration settings (see
Ta b l e 5. 2), this pin will be sampled at RESET_N negation to
determine the mode as follows:
‘0’ = Individual sensing & switching, and LED_B3_N is active
high.
‘1’ = Ganged sensing & switching, and LED_B3_N is active low.
LED_B[2:1]_N/
BOOST[1:0]
48
50
I/O12 Enhanced Port [2:1] LED & PHY Boost strapping option
Enhanced Indicator LED for ports 1 & 2. Will be active low when
LED support is enabled via EEPROM or SMBus.
BOOST[1:0]: If this strap is enabled by package and configuration
settings (see Ta b le 5.2), this pin will be sampled at RESET_N
negation to determine if all PHY ports (upstream and
downstream) operate at a normal or boosted electrical level. Also,
the active state of the LEDs will be determined as follows:
See Section 7.2.1.26, "Register F6h: Boost_Up" and Section
7.2.1.28, "Register F8h: Boost_4:0".
BOOST[1:0] = BOOST_IOUT[1:0]
BOOST[1:0] = ‘00’,
LED_B2_N is active high,
LED_B1_N is active high.
BOOST[1:0] = ‘01’,
LED_B2_N is active high,
LED_B1_N is active low.
BOOST[1:0] = ‘10’,
LED_B2_N is active low,
LED_B1_N is active high.
BOOST[1:0] = ‘11’,
LED_B2_N is active low,
LED_B1_N is active low.
Table 5.1 USB2517 Pin Descriptions (continued)
SYMBOL 64 QFN
BUFFER
TYPE DESCRIPTION