Datasheet
LAN9514/LAN9514I
DS00002306A-page 28 2009-2016 Microchip Technology Inc.
TABLE 3-4: CONFIG DATA BYTE 1 REGISTER (CFG1) FORMAT
Bits Description Default
7 Self or Bus Power (SELF_BUS_PWR)
Selects between Self or Bus-Powered operation.
0 = Bus-Powered
1 = Self-Powered
The Hub is either Self-Powered (draws less than 2 mA of upstream bus power) or
Bus-Powered (limited to a 100 mA maximum of upstream power prior to being
configured by the host controller).
When configured as a Bus-Powered device, the SMSC Hub consumes less than
100 mA of current prior to being configured. After configuration, the Bus-Powered
SMSC Hub (along with all associated hub circuitry, any embedded devices if part of
a compound device, and 100 mA per externally available downstream port) must
consume no more than 500 mA of upstream VBUS current. The current consumption
is system dependent, and the OEM must ensure that the USB 2.0 specifications are
not violated.
When configured as a Self-Powered device, <1mA of upstream VBUS current is
consumed and all ports are available, with each port being capable of sourcing
500 mA of current.
1b
6 RESERVED 0b
5 High Speed Disable (HS_DISABLE)
Disables the capability to attach as either a High/Full-Speed device, and forces
attachment as Full-Speed only (no High-Speed support).
0 = High-/Full-Speed
1 = Full-Speed-Only (High-Speed disabled)
0b
4 Multiple TT Enable (MTT_ENABLE)
Enables one transaction translator per port operation.
Selects between a mode where only one transaction translator is available for
all ports (Single-TT), or each port gets a dedicated transaction translator (Multi-
TT).
Note:
The host may force Single-TT mode only.
0 = Single TT for all ports.
1 = One TT per port (multiple TT's supported)
1b
3 EOP Disable (EOP_DISABLE)
Disables EOP generation of EOF1 when in Full-Speed mode. During FS operation
only, this permits the Hub to send EOP if no downstream traffic is detected at EOF1.
See Section 11.3.1 of the USB 2.0 Specification for additional details.
Note: Generation of an EOP at the EOF1 point may prevent a Host controller
(operating in FS mode) from placing the USB bus in suspend.
0 = An EOP is generated at the EOF1 point if no traffic is detected.
1 = EOP generation at EOF1 is disabled (note: this is normal USB operation).
Note: This is a rarely used feature in the PC environment, existing drivers may
not have been thoroughly debugged with this feature enabled. It is included
because it is a permitted feature in Chapter 11 of the USB specification.
1b