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High Speed Inter-Chip USB 2.0 Hub and Flash Media Controller
Datasheet
SMSC USB4640/USB4640i 37 Revision 1.0 (06-01-09)
DATASHEET
8.4.2 A0h-A7h: Device Power Configuration
The USB4640/USB4640i has one internal FET 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 Section 8.4.1.19, "9Ch-9Fh: Attribute Byte Descriptions," on
page 36.
8.4.2.1 A0h-A1h: Memory Stick Device Power Configuration
8.4.2.2 A2h-A3h: Not Applicable
2 ATT_LHB 0 Attach on Card Insert / Detach on Card Removal
‘1’ - Attach on Insert is enabled.
‘0’ (default) - Attach on Insert is disabled.
1 Always reads ‘0’.
2 Enable Device Power Configuration
‘1’ - Custom Device Power Configuration stored in the NVSTORE is used.
‘0’ (default) - Default Device Power Configuration is used.
7:3 Always reads ‘0’.
3 ATT_HB 6:0 Always reads ‘0’.
7 xD Player Mode
FET TYPE BITS BIT TYPE DESCRIPTION
0 FET Lo Byte
MS_PWR_LB
3:0 Low Nibble 0000b Disabled
1 7:4 High Nibble
2 FET Hi Byte
MS_PWR_HB
3:0 Low Nibble 0000b Disabled
0001b External FET enabled
1000b Internal FET with 100 mA power limit
1010b Internal FET with 200 mA power limit
3 7:4 High Nibble 0000b Disabled
BYTE NAME DESCRIPTION
1:0 Not Applicable Not applicable.
BYTE
BYTE
NAME BIT DESCRIPTION