USB2251-NU-05 Standard Microsystems (SMSC), USB2251-NU-05 Datasheet - Page 24

• Manufacturer Part Number: USB2251-NU-05
• Description: ULTRA FAST USB 2.0 MULTI-SLOT FLASH MEDI
• Manufacturer: Standard Microsystems (SMSC)

Specifications of USB2251-NU-05

• Lead Free Status / RoHS Status: Supplier Unconfirmed

Chapter 8 Configuration Options
Revision 2.0 (09-29-09)
8.1
8.1.1
8.2
8.2.1
The SMSC USB2250/50i/51/51i is fully compliant with the following flash media card reader
specifications:
VBus Detect
According to Section 7.2.1 of the USB 2.0 Specification, a device cannot provide power to its D+ or
D- pull-up resistors unless the upstream port’s VBUS is in the asserted (powered) state. The
VBUS_DET pin on the device monitors the state of the upstream VBUS signal and will not pull-up the
D+ resistor if VBUS is not active. If VBUS goes from an active to an inactive state (not powered), the
device will remove power from the D+ pull-up resistor within 10 seconds.
EEPROM
The USB2250/50i/51/51i can be configured via a 2-wire (I
the options for the USB2250/50i/51/51i. If an external configuration device does not exist the internal
default values will be used. If one of the external devices is used for configuration, the OEM can update
the values through the USB interface. The device will then “attach” to the upstream USB host.
The USBDM tool set is available in the USB224x/USB225x Card Reader software release package.
To download the software package from SMSC's website, please visit:
https://www2.smsc.com/mkt/CW_SFT_PUB.nsf/Agreements/OBJ+Card+Reader
to go to the
check the "I agree" box and then select “Confirm”. You will then be able to download the
USB224x/USB225x Card reader combo release package zip file containing the USBDM tool set.
Please note that the following applies to the system values and descriptions when used:
Card Reader
System Configurations
Compact Flash 4.1
- CF UDMA Modes 0-4
- CF PIO Modes 0-6
Secure Digital 2.0
- HS-SD and HC-SD
- TransFlash™ and reduced form factor media
MultiMediaCard 4.2
- 1/4/8 bit MMC
Memory Stick 1.43
Memory Stick Pro Format 1.02
Memory Stick Pro-HG Duo Format 1.01
- Memory Stick, MS Duo, HS-MS, MS Pro-HG, MS Pro
Memory Stick Duo 1.10
Smart Media 1.3
xD-Picture Card 1.2
N/A = Not applicable to this part
Reserved = For internal use
OBJ Card Reader Software Download
DATASHEET
24
Agreement. Review the license, and if you agree,
Ultra Fast USB 2.0 Multi-Slot Flash Media Controller
2
C) EEPROM (512x8) flash device containing
SMSC USB2250/50i/51/51i
Datasheet