SMSC USB2250 Manual De Usuario

Ultra Fast USB 2.0 Multi-Slot Flash Media Controller

Revision 1.1 (05-29-08)

14

SMSC USB2250/50i/51/51i

SM Busy or Data 
Ready

SM_nB/R

56

IPU

This pin is connected to the BSY/RDY pin of 
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 Chip Enable

SM_nCE

54

O12PU

This pin is the active low chip enable signal 
to 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 Card 
Detection GPIO

GPIO14

(SM_nCD)

57

I/O12

This is a GPIO designated as the Smart 
Media card detection pin.

MS  Bus  State

MS_BS

91

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 Card 
Insertion GPIO

 GPIO12

(MS_INS)

98

IPU

This is a GPIO designated as the Memory 
Stick card detection pin.

MS System CLK

MS_SCLK

101

O12

This pin is an output clock signal to the MS 
device.

The clock frequency is software configurable.

MS System Data 
In/Out

MS_D[7:1] 100

97
93
95
99
96
92

I/O12PD

MS_D[7:0]: These pins are the bi-directional 
data signals for the MS device. 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.