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SMSC USB2250i User Manual

Page 13

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Ultra Fast USB 2.0 Multi-Slot Flash Media Controller

Datasheet

SMSC USB2250/50i/51/51i

13

Revision 1.1 (05-29-08)

DATASHEET

SM Address
Strobe

SM_ALE

52

O12PD

This pin is an active high Address Latch
Enable signal for the SM device.

This pin has a weak pull-down resistor that
is permanently enabled.

SM Command
Strobe

SM_CLE

53

O12PD

This pin is an active high Command Latch
Enable signal for the SM device.

This pin has a weak pull-down resistor that
is permanently enabled.

SM Data 7-0

SM_D[7:0]

39
40
41
42
43
44
45
46

I/O12PD

These pins are the bi-directional data signals
SM_D7-SM_D0.

The bi-directional data signal has an internal
weak pull-down resistor.

SM Read Enable

SM_nRE

55

O12PU

This pin is an active low read strobe signal
for the SM device.

When using the internal FET, this pin has an
internal weak pull-up resistor that is tied to
the output of the internal Power FET, and is
controlled by the SM_PU bit of the
SMC_CTL register.

If an external FET is used (Internal FET is
disabled), then the internal pull-up is not
available (external pull-ups must be used).

SM Write Enable

SM_nWE

48

O12PU

This pin is an active low write strobe signal
for SM device.

When using the internal FET, this pin has an
internal weak pull-up resistor that is tied to
the output of the internal Power FET, and is
controlled by the SM_PU bit of the
SMC_CTL register.

If an external FET is used (Internal FET is
disabled), then the internal pull-up is not
available (external pull-ups must be used).

SM Write Protect
Switch

SM_nWPS

38

IPU

A write-protect seal is detected when this pin
is low.

This pin has an internal weak pull-up resistor
that is controlled by the SM_INTF_EN bit of
the SMC_MODE_CTL2 register.

Table 5.1 USB2250/50i/51/51i 128-Pin VTQFP Pin Descriptions (continued)

NAME

SYMBOL

128-PIN

VTQFP

BUFFER

TYPE

DESCRIPTION

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