2009 - 2015 Microchip Technology Inc. DS00002005A-page 21
USB2250/50i/51/51i
7.0 CONFIGURATION OPTIONS
7.1 Card Reader
The Microchip USB2250/50i/51/51i is fully compliant with the following flash media card reader specifications:
• 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
7.1.1 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.
7.2 System Configurations
7.2.1 EEPROM
The USB2250/50i/51/51i can be configured via a 2-wire (I
2
C) EEPROM (512x8) flash device containing 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 USB225x Card Reader software release package. To download the software
package from Microchip's website, please visit:
http://www.microchip.com/SWLibraryWeb/producttc.aspx?product=OBJ%20files%20for%20USB2250
to go to the OBJ Card Reader Software Download Agreement. Review the license, and if you agree, check the "I agree"
box and then select “Confirm”. You will then be able to download the USB225x Card reader combo release package zip
files containing the USBDM tool set. Please note that the following applies to the system values and descriptions when
used:
• N/A = Not applicable to this part
• Reserved = For internal use
