USB 2.0 Hi-Speed Hub Controller

Datasheet

Table 5.2 USB251x Pin Descriptions (continued)

 

BUFFER

 

SYMBOL

TYPE

DESCRIPTION

 

 

 

 

 

SERIAL PORT INTERFACES

 

 

 

SDA /

I/OSD12

Serial Data signal (SDA)

 

 

 

SMBDATA /

 

Server Message Block Data signal (SMBDATA)

 

 

 

NON_REM[1]

 

Non-removable port strap option

 

 

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

 

 

this pin will be sampled (in conjunction with LOCAL_PWR / SUSP_IND /

 

 

NON_REM[0]) at RESET_N negation to determine if ports [7:1] contain

 

 

permanently attached (non-removable) devices:

 

 

NON_REM[1:0] = ‘00’, All ports are removable.

 

 

NON_REM[1:0] = ‘01’, Port 1 is non-removable.

 

 

NON_REM[1:0] = ‘10’, Ports 1 & 2 are non-removable.

 

 

NON_REM[1:0] = ‘11’, When available, ports 1 2 & 3 are non-removable.

 

 

 

RESET_N

IS

RESET Input

 

 

The system can reset the chip by driving this input low. The minimum active

 

 

low pulse is 1 μs.

 

 

 

SCL /

I/OSD12

Serial Clock (SCL)

 

 

 

SMBCLK /

 

System Management Bus Clock (SMBCLK)

 

 

 

CFG_SEL[0]

 

Configuration Select: The logic state of this multifunction pin is internally

 

 

latched on the rising edge of RESET_N (RESET_N negation), and will

 

 

determine the hub configuration method as described in Table 8.1, "Hub

 

 

Configuration Options".

 

 

 

HS_IND /

I/O12

Hi-Speed Upstream Port Indicator

 

 

HS_IND: Hi-speed Indicator for upstream port connection speed.

 

 

The active state of the LED will be determined as follows:

 

 

CFG_SEL[1] = ‘0’,

 

 

HS_IND is active high,

 

 

CFG_SEL[1] = ‘1’,

 

 

HS_IND is active low,

 

 

‘Asserted’ = the hub is connected at HS

 

 

‘Negated’ = the hub is connected at FS

CFG_SEL[1]

 

 

 

Configuration Programming Select

 

 

 

 

CFG_SEL[1]: The logic state of this pin is internally latched on the rising edge

 

 

of RESET_N (RESET_N negation), and will determine the hub configuration

 

 

method as described in Table 8.1, "Hub Configuration Options".

 

 

 

CFG_SEL[2]

I

Configuration Programming Select

 

 

The logic state of this pin is internally latched on the rising edge of RESET_N

 

 

(RESET_N negation), and will determine the hub configuration method as

 

 

described in Table 8.1, "Hub Configuration Options". When the CFG_SEL[2]

 

 

pin is unavailable, then the logic is internally tied to ‘0’.

 

 

 

SMSC USB251x

25

Revision 1.0 (3-11-09)

DATASHEET