Ultra Fast USB 2.0 Multi-Format Flash Media Controller
Datasheet
Chapter 5 Pin Descriptions
This section provides a detailed description of each signal. The signals are arranged in functional
groups according to their associated interface.
The “n” symbol in the signal name indicates that the active, or asserted, state occurs when the signal
is at a low voltage level. When “n” is not present before the signal name, the signal is asserted at the
high voltage level.
The terms assertion and negation are used exclusively. This is done to avoid confusion when working
with a mixture of “active low” and “active high” signals. The term assert, or assertion, indicates that a
signal is active, independent of whether that level is represented by a high or low voltage. The term
negate, or negation, indicates that a signal is inactive.
5.1
Pin Descriptions
Table 5.1 USB2240/USB2241 36-Pin QFN Pin Descriptions
36-PIN
QFN
BUFFER
TYPE
NAME
SYMBOL
DESCRIPTION
xD INTERFACE (APPLIES ONLY TO USB2240)
xD Data
xD_D[7:0]
20
23
25
30
4
I/O12PD
The bi-directional data signal has an internal weak
pull-down resistor.
5
7
8
xD Write
Protect
xD_nWP
xD_ALE
9
O12PD
O12PD
This pin is an active low write protect signal for the
xD device. This pin has a weak pull-down resistor
that is permanently enabled.
xD Address
Strobe
10
This pin is an active high Address Latch Enable
signal for the xD device.
This pin has a weak pull-down resistor that is
permanently enabled.
xD Command
Strobe
xD_CLE
xD_nRE
11
16
O12PD
O12PU
This pin is an active high Command Latch Enable
signal for the xD device.
This pin has a weak pull-down resistor that is
permanently enabled.
xD Read
Enable
This pin is an active low read strobe signal for xD
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 SM_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).
SMSC USB2240/USB2241
Revision 2.6 (05-08-08)
DATA1S3HEET
SMSC [ SMSC CORPORATION ]
