USB2251-NU-05 Standard Microsystems (SMSC), USB2251-NU-05 Datasheet - Page 31

• 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

Ultra Fast USB 2.0 Multi-Slot Flash Media Controller
Datasheet
SMSC USB2250/50i/51/51i
8.2.4
8.2.4.1
8.2.4.2
8.2.4.3
FET
FET
FET
0
1
2
3
0
1
2
3
0
1
MS_PWR_HB
MS_PWR_LB
CF_PWR_HB
SM_PWR_LB
CF_PWR_LB
FET Lo Byte
FET Hi Byte
FET Lo Byte
FET Hi Byte
FET Lo Byte
A0h-A7h: Device Power Configuration
The USB2250/50i/51/51i has four internal FETs which can be utilized for card power. This section
describes the default internal configuration. The settings are stored in NVSTORE and provide the
following features:
1. A card can be powered by an external FET or by an internal FET.
2. The power limit can be set to 100 mA or 200 mA (Default) for the internal FET.
Each media uses two bytes to store its device power configuration. Bit 3 selects between internal or
external card power FET options. For internal FET card power control, bits 0 through 2 are used to
set the power limit. The “Device Power Configuration” bits are ignored unless the “Enable Device
Power Configuration” bit is set. See
page
A0h-A1h: Memory Stick Device Power Configuration
A2h-A3h: Compact Flash Device Power Configuration
A4h-A5h: Smart Media Device Power Configuration
TYPE
TYPE
TYPE
30.
BITS
BITS
BITS
3:0
3:0
3:0
7:4
7:4
3:0
7:4
7:4
3:0
7:4
Low Nibble
High Nibble
Low Nibble
High Nibble
Low Nibble
High Nibble
Low Nibble
High Nibble
Low Nibble
High Nibble
BIT TYPE
BIT TYPE
BIT TYPE
DATASHEET
Section 8.2.3.19, "9Ch-9Fh: Attribute Byte Descriptions," on
31
0000b Disabled
0000b Disabled
0001b External FET enabled
1000b Internal FET with 100 mA power limit
1010b Internal FET with 200 mA power limit
0000b Disabled
0000b Disabled
0000b Disabled
0001b External FET enabled
1000b Internal FET with 100 mA power limit
1010b Internal FET with 200 mA power limit
0000b Disabled
0000b Disabled
DESCRIPTION
DESCRIPTION
DESCRIPTION
Revision 2.0 (09-29-09)