Datasheet

USB 2.0 Hi-Speed 7-Port Hub Controller
Datasheet
Revision 2.8 (09-17-12) 14 SMSC USB2517
DATASHEET
CFG_SEL2 13 I Configuration Programming Select
Note: This pin is not available in all packages; it is held to a
logic ‘0’ when not available.
The logic state of this pin is internally latched on the rising edge
of RESET_N (RESET_N negation), and will determine the hub
configuration method as described in Table 5.2, "USB2517
SMBUS or EEPROM Interface Behavior".
MISC
XTAL1/
CLKIN
61 ICLKx Crystal Input/External Clock Input
24MHz crystal or external clock input.
This pin connects to either one terminal of the crystal or to an
external 24MHz clock when a crystal is not used.
XTAL2 60 OCLKx Crystal Output
24MHz Crystal
This is the other terminal of the crystal. It can be treated as a no
connect when an external clock source is used to drive
XTAL1/CLKIN. This output must not be used to drive any external
circuitry other than the crystal circuit.
RESET_N 43 IS RESET Input
The system can reset the chip by driving this input low. The
minimum active low pulse is 1 μs.
When the RESET_N pin is pulled to VDD33, the internal POR
(Power on Reset) is enabled and no external reset circuitry is
required. The internal POR holds the internal logic in reset until
the power supplies are stable.
SUSP_IND/
LOCAL_PWR/
NON_REM0
45 I/O12 Active/Suspend status LED or Local-Power & Non-Removable
Strap Option
Suspend Indicator: Indicates the USB state of the hub.
‘negated’ = Unconfigured or configured and in USB suspend
‘asserted’ = Hub is configured, and is active (i.e., not in suspend)
Local Power: Detects availability of local self-power source.
Low = Self/local power source is NOT available (i.e., Hub gets all
power from the upstream USB VBus).
High = Self/local power source is available.
NON_REM0 Strap Option:
If this strap is enabled by package and configuration settings (see
Table 5.2, "USB2517 SMBUS or EEPROM Interface Behavior"),
this pin will be sampled (in conjunction with NON_REM1) at
RESET_N negation to determine if ports [3:1] contain
permanently attached (non-removable) devices. Also, the active
state of the LED will be determined as follows:
NON_REM[1:0] = ‘00’, All ports are removable, and the LED is
active high
NON_REM[1:0] = ‘01’, Port 1 is non-removable, and the LED is
active low
NON_REM[1:0] = ‘10’, Ports 1 & 2 are non-removable, and the
LED is active high
NON_REM[1:0] = ‘11’, Ports 1, 2 & 3 are non-removable, and the
LED is active low
Table 5.1 USB2517 Pin Descriptions (continued)
SYMBOL 64 QFN
BUFFER
TYPE DESCRIPTION