USB2251-NU-05 Standard Microsystems (SMSC), USB2251-NU-05 Datasheet - Page 34

• 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

Revision 2.0 (09-29-09)
8.2.5.8
8.2.5.9
8.2.5.10
8.3
8.3.1
BYTE
BYTE
BYTE
35:0
3:0
3:0
D4h-D7h: Device to LUN Mapping
D8h-FBh: Not Applicable
FCh-FFh: Non-Volatile Storage Signature
The SMSC device can be configured via its internal default configuration. Please see
"EEPROM Data Descriptor"
Table 8.1
External Hardware nRESET
A valid hardware reset is defined as assertion of nRESET for a minimum of 1 μs after all power
supplies are within operating range. While reset is asserted, the device (and its associated external
circuitry) consumes less than 500 μA of current.
Assertion of nRESET (external pin) causes the following:
1. The PHY is disabled and the differential pair will be in a high-impedance state.
2. All transactions immediately terminate; no states are saved.
3. All internal registers return to the default state.
4. The external crystal oscillator is halted.
5. The PLL is halted.
6. The processor is reset.
7. All media interfaces are reset.
Default Configuration Option
NVSTORE_SIG
DEV_LUN_MAP
Not Applicable
NAME
NAME
NAME
for the internal default values that are loaded when this option is selected.
This signature is used to verify the validity of the data in the first 256 bytes of
the configuration area. The signature must be set to ‘ATA2’ for
USB2250/50i/51/51i.
These registers map a device controller (SD/MMC, SM, and MS) to a Logical
Unit Number (LUN). The device reports the mapped LUNs to the USB host
in the USB descriptor during enumeration. The icon installer associates
custom icons with the LUNs specified in these fields.
Setting a register to "FF" indicates that the device is not mapped. Setting all
of the DEV_LUN_MAP registers for all devices to "FF" forces the use of the
default mapping configuration. Not all configurations are valid. Valid
configurations depend on the hardware, packaging, and OEM board layout.
The number of unique LUNs mapped must match the value in the
8.2.5.7, "D3h: Dynamic Number of LUNs," on page
Not Applicable.
for specific details on how to enable default configuration. Please refer to
DATASHEET
34
DESCRIPTION
DESCRIPTION
DESCRIPTION
Ultra Fast USB 2.0 Multi-Slot Flash Media Controller
33.
SMSC USB2250/50i/51/51i
Section 8.2.2,
Section
Datasheet