Integrated USB 2.0 Compatible 4-Port Hub
Datasheet
Revision 2.3 (08-27-07)
20
SMSC USB2504/USB2504A
DATASHEET
5.2.1.2
Pull-Up Resistor
The Circuit board designer is required to place external pull-up resistors (10K
Ω
recommended) on the
SDA/SMBDATA & SCL/SMBCLK/CFG_SELO lines (per SMBus 1.0 Specification, and EEPROM
manufacturer guidelines) to Vcc in order to assure proper operation.
5.2.1.3
I2C EEPROM Slave Address
Slave address is 1010000.
Note:
10-bit addressing is NOT supported.
5.2.2
In-Circuit EEPROM Programming
The EEPROM can be programmed via ATE by pulling RESET_N low (which tri-states the Hub’s
EEPROM interface and allows an external source to program the EEPROM).
5.2.3
EEPROM DATA
Table 5.1 User-Defined Descriptor Data
FIELD
BYTE
MSB:
LSB
SIZE
(BYTES)
DEFAULT
CFG
SELF
(HEX)
DEFAULT
CFG
BUS
(HEX)
DESCRIPTION
VID
1:0
2
0424
0424
Vendor ID (assigned by USB-IF).
PID
3:2
2
4-port =
2504
4-Port =
2504
Product ID (assigned by Manufacturer).
DID
5:4
2
0000
0000
Device ID (assigned by Manufacturer).
Config Data
Byte 1
6
1
98
1C
Configuration data byte #1 for Hub options.
Config Data
Byte 2
7
1
90
90
Configuration data byte #2 for Hub options.
Non
Removable
Device
8
1
00
00
Defines the ports that contain attached
devices (this is used only when Hub is part of
a compound device).
Port Disable
Self-Powered
9
1
00
00
Selects the ports that will be permanently
disabled
Port Disable
Bus-Powered
A
1
00
00
Selects the ports that will be permanently
disabled
Max Power
Self-Powered
B
1
01
01
Max Current for this configuration (expressed
in 2mA units).
Max Power
Bus-Powered
C
1
64
64
Max Current for this configuration (expressed
in 2mA units).
Hub Controller
Max Current
Self-Powered
D
1
01
01
Max Current (expressed in 2mA units).
Hub Controller
Max Current
Bus-Powered
E
1
64
64
Max Current (expressed in 2mA units).
Power-On
Time
F
1
32
32
Time until power is stable.
