Ultra Fast USB 2.0 SD/MMC Flash Media Controller

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Table 5.2 USB2244/2244i 36-Pin QFN Pin Descriptions (continued)

 

 

36-PIN

BUFFER

 

NAME

SYMBOL

QFN

TYPE

DESCRIPTION

 

 

 

 

 

24MHz Crystal

XTAL1

33

ICLKx

This pin can be connected to one terminal of

or external clock

(CLKIN)

 

 

the crystal or it can be connected to an external

input

 

 

 

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

VDDA33

36

 

3.3V Analog Power

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 1.0μF(or greater) ±20%

 

 

 

 

(ESR <0.1Ω) capacitor to VSS.

 

 

 

 

 

 

 

 

MISC

 

 

 

 

 

 

General Purpose

GPIO1 (LED1)

1

I/O12

This pin may be used either as input, edge

I/O

 

 

 

sensitive interrupt input, or output.

 

 

 

 

In addition, as an output, the GPIO1 can use

 

 

 

 

output controlled by the LED1_GPIO1 register.

 

 

 

 

 

General Purpose

GPIO2 / RXD /

27

I/O12

GPIO: This pin may be used either as input,

I/O

SDA

 

 

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

GPIO4

29

I/O12

This pin may be used either as input, edge

I/O

 

 

 

sensitive interrupt input, or output.

 

 

 

 

 

General Purpose

GPIO7 /

31

I/O12

GPIO: This pin may be used either as input,

I/O

TXD /

 

 

edge sensitive interrupt input, or output.

 

SCK

 

 

 

 

 

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

GPIO10

21

I/O200

GPIO: This pin may be used either as input,

I/O

(CRD_PWR)

 

 

edge sensitive interrupt input, or output.

 

 

 

 

 

 

 

 

 

CRD_PWR: Card Power drive of 3.3V @ either

 

 

 

 

100mA or 200mA.

 

 

 

 

 

General Purpose

GPIO14

19

I/O12

This pin may be used either as input, edge

I/O

 

 

 

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 1μs wide.

 

 

 

 

 

SMSC USB2244/USB2244i

 

11

Revision 1.0 (05-27-08)

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