Ultra Fast USB 2.0
7.3.2.10A4h-A5h: LUN Power Configuration
The USB2640/USB2641 has one internal FET which can be utilized for card power. The settings are stored in NVSTORE and provide the following features:
1.A card can be powered by an external FET or internal FET.
2.The power limit can be set to 100 mA (Default) or 200 mA for the internal FET.
Each media uses two bytes to store its LUN power configuration. Bit 3 selects between internal or external. For internal FETs Bits 0 through 2 are used for the power limit. Only 2 of the possible 8 values are currently specified.
Table 7.4 FET Configuration
FET | TYPE | BITS | BIT TYPE |
| DESCRIPTION | |
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0 | FET Low | 3:0 | Low Nibble | Unused. | ||
| Byte |
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| |
1 | 7:4 | High Nibble | Unused. | |||
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2 | FET High | 3:0 | Low Nibble | 0000b Disabled. | ||
| Byte |
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| 0001b | External FET Enabled. | |
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| 1000b | Internal FET with 100 mA power limit. | |
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| 1010b | Internal FET with 200 mA power limit. | |
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3 |
| 7:4 | High Nibble | Unused. | ||
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7.3.2.11A8h: LED Blink Interval (1 byte)
BIT |
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NUMBER | BIT NAME | DESCRIPTION |
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7:0 | LED_BLK_INT | The blink rate is programmable in 10 ms intervals. Hi bit indicates idle state: |
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| to a max of 128 x 10 ms. |
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7.3.2.12A9h: Blink Duration (1 byte)
BIT |
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NUMBER | BIT NAME | DESCRIPTION |
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7:0 | LED_BLK_DUR | LED blink After Access. This byte is used to designate the number of |
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| seconds that the GPIO 0 LED will continue to blink after a drive access. |
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| Setting this byte to "05" will cause the GPIO 0 LED to blink for 5 seconds |
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| after a drive access. |
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There are four LUN ID strings corresponding to LUN# 0, 1, 2, and 3: Number of Icons to Display, SM LUN #, MS LUN #, SD/MMC LUN #. The SM value will be overridden with xD once an
SMSC USB2640/USB2641 | 33 | Revision 2.0 |
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