USB 2.0
Datasheet
8.2.1.7Register 06h: CONFIG_BYTE_1
BIT |
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NUMBER | BIT NAME | DESCRIPTION |
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7 | SELF_BUS_PWR | Self or Bus Power: Selects between Self- and |
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| The hub is either |
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| power) or |
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| prior to being configured by the host controller). |
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| When configured as a |
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| than 100 mA of current prior to being configured. After configuration, the bus- |
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| powered SMSC hub (along with all associated hub circuitry, any embedded |
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| devices if part of a compound device, and 100 mA per externally available |
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| downstream port) must consume no more than 500 mA of upstream VBUS |
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| current. The current consumption is system dependent, and the OEM must |
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| ensure that the USB 2.0 specifications are not violated. |
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| When configured as a |
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| current is consumed and all ports are available, with each port being capable |
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| of sourcing 500 mA of current. |
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| This field is set by the OEM using either the SMBus or EEPROM interface |
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| options. |
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| Please see the description under dynamic power for the |
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| functionality when dynamic power switching is enabled. |
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| '0' = |
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| ’1’ = |
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| If dynamic power switching is enabled, this bit is ignored and the |
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| LOCAL_PWR pin is used to determine if the hub is operating from self or |
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| bus power. |
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6 | Reserved | Reserved |
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5 | HS_DISABLE | |
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| device, and forces attachment as |
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| '0' = |
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| ‘1’ = |
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4 | MTT_ENABLE | |
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| (Not available on the USB2512A/12Ai.) |
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| Selects between a mode where only one transaction translator is available |
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| for all ports |
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| |
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| '0' = Single TT for all ports |
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| ‘1’ = One TT per port (when multiple TT's are supported) |
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3 | EOP_DISABLE | EOP Disable: Disables EOP generation at EOF1 when in |
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| During FS operation only, this permits the hub to send EOP if no |
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| downstream traffic is detected at EOF1. See Section 11.3.1 of the USB 2.0 |
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| specification for additional details. |
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| '0' = EOP generation is normal |
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| ‘1’ = EOP generation is disabled |
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Revision 1.0 | 38 | SMSC USB251x |
DATASHEET