USB MultiSwitchTM Hub
Datasheet
Table 4.2 SMBus or EEPROM Interface Behavior (continued)
NAME
NAME
NAME
FUNCTION
Internal Default Configuration
1
0
0
PRT_ASSIGN[3:0] = Peripheral Mode (Edge Triggered)
LED Mode = Host Ownership Mode
Strap
options on pins LED_A[4:1]_N are enabled.
Supports unassigned Ports
1
0
1
Internal Default Configuration
PRT_ASSIGN[3:0] = Peripheral Mode (Edge Triggered)
LED Mode = Host Ownership & Port Speed Mode
Strap options on pins LED_A[4:1]_N are disabled
Supports unassigned Ports.
1
1
1
1
0
1
Reserved
Reserved
Table 4.3 Miscellaneous Pins
TYPE
NAME
SYMBOL
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.
Note:
See Table 11.1 for the required logic voltage
levels of this pad if it will be driven by an
external clock source.
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.
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 Pin
TEST
IPD
Used for testing the chip. User must treat as a no-
connect or connect to ground.
Table 4.4 Power, Ground, and No Connect
NAME
SYMBOL
TYPE
FUNCTION
VDD Core
VDDCR18
+1.8V core power.
Pins 16 and 50 must have a 4.7μF (or greater) ±20%
(ESR <0.1Ω) capacitor to VSS
VDDIO 3.3V
VDD33
+3.3V Power Supply for the Digital I/O.
SMSC USB2524
Revision 1.91 (08-22-07)
DATA1S5HEET
SMSC [ SMSC CORPORATION ]
