USB 2.0 Hi-Speed Hub Controller

Datasheet

 

 

Table 5.2 USB251x Pin Descriptions (continued)

 

 

 

 

BUFFER

 

SYMBOL

TYPE

 

DESCRIPTION

 

 

 

 

 

 

 

MISC

 

 

 

 

XTALIN

ICLKx

 

Crystal Input

 

 

 

24 MHz crystal

 

 

 

This pin connects to either one terminal of the crystal or to an external

 

 

 

24 MHz clock when a crystal is not used.

 

 

 

 

CLKIN

 

 

External Clock Input

 

 

 

This pin connects to either one terminal of the crystal or to an external

 

 

 

24 MHz clock when a crystal is not used.

 

 

 

 

XTALOUT

OCLKx

 

Crystal Output

 

 

 

24 MHz Crystal

 

 

 

This is the other terminal of the crystal, or a no connect pin, when an external

 

 

 

clock source is used to drive XTALIN/CLKIN.

 

 

 

 

SUSP_IND /

I/O

 

Active/Suspend status LED

 

 

 

Suspend Indicator: Indicates USB state of the hub.

 

 

 

‘negated’ = Unconfigured, or configured and in USB Suspend

 

 

 

‘asserted’ = the hub is configured, and is active (i.e., not in suspend)

LOCAL_PWR /

 

 

 

 

 

Local Power: Detects availability of local self-power source.

 

 

 

 

 

 

Low = Self/local power source is NOT available (i.e., the hub gets all power

 

 

 

from Upstream USB VBus).

 

 

 

High = Self/local power source is available.

NON_REM[0]

 

 

 

 

 

NON_REM[0] Strap Option:

 

 

 

 

 

 

If this strap is enabled by package and configuration settings (see Table 8.1,

 

 

 

"Hub Configuration Options"), this pin will be sampled (in conjunction with

 

 

 

NON_REM[1]) at RESET_N negation to determine if ports [x: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’, When available, ports 1, 2 & 3 are non-removable, and

 

 

 

the LED is active low

 

 

 

 

TEST

IPD

 

TEST pin

 

 

 

User must treat as a no connect pin or connect to ground. No trace or signal

 

 

 

should be routed or attached to this pin.

 

 

 

 

Revision 1.0 (3-11-09)

26

SMSC USB251x

DATASHEET