82NM10 Datasheet, PDF (538/671 Pages) Intel Corporation – Intel® NM10 Family Express Chipset

EHCI Controller Registers (D29:F7)
Bit
Description
5 Asynchronous Schedule Enable — R/W. Default 0b. This bit controls whether the
host controller skips processing the Asynchronous Schedule.
0 = Do not process the Asynchronous Schedule
1 = Use the ASYNCLISTADDR register to access the Asynchronous Schedule.
4 Periodic Schedule Enable — R/W. Default 0b. This bit controls whether the host
controller skips processing the Periodic Schedule.
0 = Do not process the Periodic Schedule
1 = Use the PERIODICLISTBASE register to access the Periodic Schedule.
3:2 Frame List Size — RO. The Chipset hardwires this field to 00b because it only
supports the
1024-element frame list size.
1 Host Controller Reset (HCRESET) — R/W. This control bit used by software to reset
the host controller. The effects of this on root hub registers are similar to a Chip
Hardware Reset
(i.e., RSMRST# assertion and PWROK deassertion on the Chipset).
When software writes a 1 to this bit, the host controller resets its internal pipelines,
timers, counters, state machines, etc. to their initial value. Any transaction currently in
progress on USB is immediately terminated. A USB reset is not driven on downstream
ports.
NOTE: PCI configuration registers and Host controller capability registers are not
effected by this reset.
All operational registers, including port registers and port state machines are set to
their initial values. Port ownership reverts to the companion host controller(s), with the
side effects described in the EHCI spec. Software must re-initialize the host controller
in order to return the host controller to an operational state.
This bit is set to 0 by the host controller when the reset process is complete. Software
cannot terminate the reset process early by writing a 0 to this register.
Software should not set this bit to a 1 when the HCHalted bit (D29:F7:CAPLENGTH +
24h, bit 12) in the USB2.0_STS register is a 0. Attempting to reset an actively running
host controller will result in undefined behavior. This reset me be used to leave EHCI
port test modes.
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Datasheet