USB2250/50i/51/51i

DS00002005A-page 26

 2009 - 2015 Microchip Technology Inc.

7.2.3.19

9Ch-9Fh: Attribute Byte Descriptions

7.2.4

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 Section 7.2.3.19, "9Ch-

9Fh: Attribute Byte Descriptions," on page 26.

Byte

Byte Name

Bit

Description

0

ATT_LB

3:0

Always reads ‘0’.

4

Inquire Manufacturer and Product ID Strings

‘1’ - Use the Inquiry Manufacturer and Product ID Strings.

‘0’ (default) - Use the USB Descriptor Manufacturer and Product ID Strings.

5

Always reads ‘0’.

6

Reverse SD Card Write Protect Sense

‘1’ (default) - SD cards will be write protected when SW_nWP is high, and

writable when SW_nWP is low.

‘0’ - SD cards will be write protected when SW_nWP is low, and writable

when SW_nWP is high.

7

Reserved.

1

ATT_HLB

3:0

Always reads ‘0’.

4

Activity LED True Polarity

‘1’ - Activity LED to Low True.

‘0’ (default) - Activity LED polarity to High True.

5

Common Media Insert / Media Activity LED

‘1’ - The activity LED will function as a common media inserted/media access

LED.

‘0’ (default) - The activity LED will remain in its idle state until media is

accessed.

6

Always reads ‘0’.

7

Reserved.

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