SMSC USB2242 - Manual (Page 10)

Ultra Fast USB 2.0 Memory Stick Flash Media Controller
Datasheet
Revision 1.0 (05-27-08) 10 SMSC USB2242/USB2242i
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 5.2 USB2242/2242i 36-Pin QFN Pin Descriptions
NAME SYMBOL 36-PIN QFN
BUFFER
TYPE DESCRIPTION
MEMORY STICK INTERFACE
MS System Data
In/Out MS_D[7:0] 8
7
4
5
23
20
10
11
I/O12PD These pins are the bi-directional data
signals for the MS device. In serial mode,
the most significant bit (MSB) of each byte
is transmitted first by either MSC or MS
device on MS_D0. MS_D0, MS_D2, and
MS_D3 have weak pull-down resistors.
MS_D1 has a pull down resistor if it is in
parallel mode, otherwise it is disabled. In
4 or 8 bit parallel mode, there is a weak
pull-down resistor on all MS_D7 - 0
signals. The resistors are controlled by
MSC_SYSTEM_0, MSC_MODE_CTL and
MSC_PRO_HG registers.
MS Bus State MS_BS 9 O12 This pin is connected to the BS pin of the
MS device.
It is used to control the Bus States 0, 1, 2
and 3 (BS0, BS1, BS2 and BS3) of the MS
device.
MS System CLK MS_SCLK 30 O12 This pin is an output clock signal to the
MS device.
The clock frequency is software
configurable.
MS Card Insertion
GPIO GPIO12
(MS_INS) 24 IPU This is a GPIO designated as the Memory
Stick
TM card detection pin.
USB INTERFACE
USB Bus Data USB+
USB- 2
3 I/O-U These pins connect to the USB bus data
signals.