Bus Powered USB2.0 Flash Media Controller
Datasheet
NAME
MS System
CLK
SD Data3-0
SD Clock
SD Command
SD Write
Protected
USB Bus Data
USB
Transceiver
Bias
Analog Test
SYMBOL
MS_SCLK
BUFFER
TYPE
O8
DESCRIPTION
This pin is an output clock signal to the MS device.
SD_DAT[3:0]
SD_CLK
SD_CMD
SD_nWP
I/O8
O8
I/O8
IPD
USB-
USB+
RBIAS
IO-U
I
SD INTERFACE
These are bi-directional data signals.
This is an output clock signal to SD/MMC device.
This is a bi-directional signal that connects to the CMD
signal of SD/MMC device.
This pin is Write Protect Switch input signal with an
internal weak pull-down.
USB INTERFACE
These pins connect to the USB bus data signals.
A 12.0KΩ
±
1% resistor is attached from ground to this
pin to set the transceiver’s internal bias currents.
This signal is used for testing the analog section of the
chip and should be connected to VDDA for normal
operation.
1.8v Analog Power
This pin MUST have a 10uf +/- 20%, (equivalent series
resistance (ESR) <0.1ohm) bypass capacitor to VSSA.
This capacitor should be placed as close to the pin as
possible.
Analog Ground Reference for 1.8v Analog power.
3.3v Analog Power
Analog Ground Reference for 3.3v Analog Power.
This pin is connected to 3.3v.
ATEST
IOA
1.8v Analog
Power
VDDP
Analog Ground
Reference
3.3v Analog
Power
Analog Ground
Reference
1.8v Voltage
Regulator for
USB PHY
Crystal
Input/External
Clock Input
VSSP
VDDA
VSSA
VREG
XTAL1/
CLKIN
ICLKx
12Mhz Crystal or external clock input.
This pin can be connected to one terminal of the crystal
or can be connected to an external 12Mhz clock when a
crystal is not used.
12Mhz Crystal
Crystal Output
XTAL2
OCLKx
Memory Data
Bus
MD[7:0]
This is the other terminal of the crystal, or 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.
MEMORY/IO INTERFACE
IO8
When using external program memory, these signals are
used to transfer data between the internal CPU and the
external program memory.
When using internal program ROM, internal weak pull up
resistors are activated to prevent these pins from floating.
Revision 1.3 (09-21-04)
Page 12
SMSC USB2224
DATASHEET
SMSC [ SMSC CORPORATION ]
