SMSC USB2512Ai, Техническое описание

Страница: 9 / 37

Industrial Temperature Rated USB 2.0 Hi-Speed 2-Port Hub Controller
Datasheet
SMSC USB2512Ai 9 Revision 1.97 (08-11-08)
DATASHEET
RBIAS 35 I-R USB Transceiver Bias
A 12.0k
Ω
(+/- 1%) resistor is attached from ground to this pin
to set the transceiver’s internal bias settings.
SERIAL PORT INTERFACE
SDA/
SMBDATA/
NON_REM1
22 I/OSD12 Serial Data / SMB Data & Port Non-removable Strap Option
NON_REM1: Non-removable port strap option.
If this strap is enabled by package and configuration settings
(see
Table 3.2, "SMBus or EEPROM Interface Behavior" ), this
pin will be sampled (in conjunction with LOCAL_PWR/
SUSP_IND/NON_REM0) at RESET_N negation to determine if
ports [2:1] 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’, Ports 1 & 2 are non-removable.
SCL/
SMBCLK/
CFG_SEL0
24 I/OSD12 Serial Clock (SCL)
SMBus Clock (SMBCLK)
Configuration Select_SEL0: 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 3.2, "SMBus or EEPROM
Interface Behavior" .
HS_IND/
CFG_SEL1
25 I/O12 Hi-Speed Upstream port indicator & Configuration
Programming Select
HS_IND: Hi-Speed Indicator for upstream port connection
speed.
The active state of the LED will be determined as follows:
CFG_SEL1 = ‘0’,
HS_IND is active high,
CFG_SEL1 = ‘1’,
HS_IND is active low,
‘Asserted’ = Hub is connected at HS
‘Negated’ = Hub is connected at FS
CFG_SEL1: 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 3.2, "SMBus or EEPROM Interface Behavior" .
MISC
XTAL1/
CLKIN
33 ICLKx Crystal Input/External Clock Input
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.
Table 3.1 USB2512Ai Pin Descriptions (continued)
SYMBOL
QFN-36
EMB
BUFFER
TYPE DESCRIPTION