4-Port USB 2.0 Controller
Datasheet
SMSC USB20H04
Page 9
Revision 1.63 (03-30-07)
DATASHEET
Chapter 4
Interface Signal Definition
4.1 Pin
Descriptions
Table 4.1 - System Interface Signals
NAME
BUFFER
TYPE
ACTIVE
LEVEL
DESCRIPTION
RESET_N
IS
Low
Chip Reset
. The minimum active low pulse is 100ns. See section 8.4 for a
complete description of operation following a reset.
SELF_PWR
I
High
Self-power Detect
. Detects availability of local self-power source:
0: Self/local power source is NOT available (i.e., 4- Port Hub gets all power
from Upstream USB V
BUS
).
1: Self/local power source is available.
TEST_P0
IPD
N/A
Test Pin.
Do Not Connect
TEST_P1
IPD
N/A
Test Pin.
Do Not Connect
TEST_P2
IPD
N/A
Test Pin.
Do Not Connect
TEST_P3
IPD
N/A
Test Pin.
Do Not Connect
ATEST
AO
N/A
Test Pin.
Do Not Connect
Table 4.2 – Configuration Select and Serial Port Interface
NAME
BUFFER
TYPE
ACTIVE
LEVEL
DESCRIPTION
SMB_SEL_N I
N/A
SMBus Select
. Selects between configuration via the SMBus interface, or
from an external EEPROM or using the internal default, as described in
the table below.
SMB_SEL_N
CS/EE_SEL
SMBus or EEPROM interface
configuration.
0
0
SMBus slave. Address: 0101100
0
1
SMBus slave. Address: 0101101
1
0
Internal default configuration.
1
1
2-wire EEPROM interface.
CS/EE_SEL IO8 N/A
Chip Select
. This multifunction pin is sampled on the rising edge of
RESET_N. If SMB_SEL_N = 1, the internal default configuration will be
used when this pin is low, or the external I2C EEPROM will supply the
configuration when this pin is high. When SMB_SEL_N = 0, this pin
selects the SMBus slave address, as described in the table above.
Connect a 1k ohm resistor in series with the input when connecting this
pin to either VDD or VSS.
SD/SDA IOSD12 N/A
Serial Data
. Data I/O on the 2-Wire interface.
SCK/SCL IOSD12 N/A
Serial Clock
. Clock for the 2-Wire interface.