Datasheet

High-Speed Inter-Chip (HSIC) USB 2.0 Hub and Flash Media Controller
Datasheet
Revision 1.3 (03-13-13) 16 SMSC USB4640/USB4640i
DATASHEET
xD_nRE 27 O8PU xD-Picture Card Read Enable
Active low read strobe signal for the xD-Picture Card device.
When using the internal FET, this pin has a weak internal pull-up
resistor that is tied to the output of the internal power FET.
If an external FET is used (internal FET is disabled), then the internal
pull-up is not available (an external pull-up is required).
xD_nWE 22 O8PU xD-Picture Card Write Enable
Active low write strobe signal for the xD-Picture Card device.
When using the internal FET, this pin has a weak internal pull-up
resistor that is tied to the output of the internal power FET.
If an external FET is used (internal FET is disabled), then the internal
pull-up is not available (an external pull-up is required).
xD_nWP 21 O8PD xD-Picture Card Write Protect
Active low write-protect signal for the xD-Picture Card device. This
pin has a weak pull-down resistor that is permanently enabled.
SPI INTERFACE
SPI_CE_n 8 O12 SPI Chip Enable
Active low chip enable output. If the SPI interface is enabled, this pin
must be driven high in power down states.
SPI_CLK/ 9 I/O12 SPI Clock Out
Clock signal out to the serial ROM. See Section 3.6: ROM BOOT
Sequence on page 21 for diagram and usage instructions. During
reset, this pin must be driven low.
GPIO4/ I/O6 General Purpose IO 4
Can be used either as input; edge sensitive interrupt input; or output.
Custom firmware is required to activate this function.
SCL Serial Clock
The I
2
C EEPROM clock pin when the device is connected to the
optional I
2
C EEPROM.
Table 3.2 USB4640/USB4640i Pin Descriptions (continued)
SYMBOL
48-PIN
QFN
BUFFER
TYPE DESCRIPTION