SMSC USB2244 User Manual
Page 11
Ultra Fast USB 2.0 SD/MMC Flash Media Controller
Datasheet
SMSC USB2244/USB2244i
11
Revision 1.0 (05-27-08)
DATASHEET
24MHz Crystal
or external clock
input
XTAL1
(CLKIN)
33
ICLKx
This pin can be connected to one terminal of
the crystal or it can be connected to an external
24 clock when a crystal is not used.
24MHz Crystal
XTAL2
32
OCLKx
This is the other terminal of the crystal, or it can
be left open when an external clock source is
used to drive XTAL1(CLKIN). It may not be
used to drive any external circuitry other than
the crystal circuit.
3.3V Analog
Power
VDDA33
36
3.3V Analog Power
1.8V PLL Power
VDD18PLL
34
This pin is the 1.8V Power for the PLL.
+1.8V Filtered analog power for internal PLL.
This pin must have a 1.0
μ
F(or greater) ±20%
(ESR <0.1
Ω) capacitor to VSS.
MISC
General Purpose
I/O
GPIO1 (LED1)
1
I/O12
This pin may be used either as input, edge
sensitive interrupt input, or output.
In addition, as an output, the GPIO1 can use
output controlled by the LED1_GPIO1 register.
General Purpose
I/O
GPIO2 / RXD /
SDA
27
I/O12
GPIO: This pin may be used either as input,
edge sensitive interrupt input, or output.
I
RXD: In addition to the above, the signal can
be used as input to the RXD of UART in the
device, when the TXD_RXD_SEL bit in
UTIL_CONFIG1 register is cleared to "0".
I/O12
SDA: This is the data pin when used with an
external serial EEPROM.
General Purpose
I/O
GPIO4
29
I/O12
This pin may be used either as input, edge
sensitive interrupt input, or output.
General Purpose
I/O
GPIO7 /
TXD /
SCK
31
I/O12
GPIO: This pin may be used either as input,
edge sensitive interrupt input, or output.
O12
TXD: In addition, as an output, the GPIO7 can
be used as an output TXD of UART in the
device, when the GPIO2/TXD bit in
UTL_CONFIG register is set to "1"
O12
SCK: This is the clock output when used with
an external EEPROM.
General Purpose
I/O
GPIO10
(CRD_PWR)
21
I/O200
GPIO: This pin may be used either as input,
edge sensitive interrupt input, or output.
CRD_PWR: Card Power drive of 3.3V @ either
100mA or 200mA.
General Purpose
I/O
GPIO14
19
I/O12
This pin may be used either as input, edge
sensitive interrupt input, or output.
RESET Input
nRESET
18
IS
This active low signal is used by the system to
reset the chip. The active low pulse should be
at least 1
μs wide.
Table 5.2 USB2244/2244i 36-Pin QFN Pin Descriptions (continued)
NAME
SYMBOL
36-PIN
QFN
BUFFER
TYPE
DESCRIPTION