Integrated USB 2.0 Compatible 7-Port Hub
Datasheet
Table 4.1 7-Port Hub Pin Descriptions (continued)
NAME
SYMBOL
TYPE
FUNCTION
SERIAL PORT INTERFACE
Serial Data/SMB
Data
SDA/SMBDATA
IOSD12
IOSD12
(Serial Data)/(SMB Data) signal.
Serial Clock/SMB
SCL/SMBCLK/
CFG_SEL0
(Serial Clock)/(SMB Clock) signal. This multifunction pin is
read on the rising edge of RESET_N (see the applicable
RESET_N timing table in Section 5.6.1) and will determine
the hub configuration method as described in Table 4.2.
Clock
&
Config Select 0
Configuration
Programming
Select
CFG_SEL1
I
This multifunction pin is read on the rising edge of
RESET_N (see the applicable RESET_N timing table in
Section 5.6.1) and will determine the hub configuration
method as described in Table 4.2.
Table 4.2 SMBus or EEPROM Interface Behavior
CFG_SEL1
CFG_SEL0
SMBus or EEPROM interface behavior.
Reserved
0
0
0
1
Configured as an SMBus slave for external download of user-
defined descriptors. SMBus slave address is 0101100
1
1
0
1
Internal Default Configuration via strapping options.
2-wire (I2C) EEPROMS are supported,
Table 4.3 Miscellaneous Pins
NAME
SYMBOL
TYPE
FUNCTION
Crystal
Input/External
Clock Input
XTAL1/
CLKIN
ICLKx
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.
Crystal Output
XTAL2
OCLKx
24MHz Crystal
This is the other terminal of the crystal, or left
unconnected when an external clock source is used to
drive XTAL1/CLKIN. It must not be used to drive any
external circuitry other than the crystal circuit.
Clock Input
Enable
CLKIN_EN
I
Clock In Enable:
Low = XTAL1 and XTAL2 pins configured for use with
external crystal
High = XTAL1 pin configured as CLKIN, and must be
driven by an external CMOS clock.
RESET Input
RESET_N
IS
I
This active low signal is used by the system to reset the
chip. The minimum active low pulse is 1us.
Self-Power /
Bus-Power
Detect
SELF_PWR
Detects availability of local self-power source.
Low = Self/local power source is NOT available (i.e., Hub
gets all power from Upstream USB VBus).
High = Self/local power source is available.
TEST Pins
TEST[1:0]
IPD
Used for testing the chip. User must treat as a no-
connect or connect to ground.
Revision 2.3 (08-27-07)
SMSC USB2507
DATA1S2HEET
SMSC [ SMSC CORPORATION ]
