USB Host Controller Registers
14-13
Universal Serial Bus Host
The HC command and status register shows the current state of the host
controller and accepts commands from the host controller driver.
Table 14–4. HC Command and Status Register (HcCommandStatus)
Bit
Name
Description
Type
Reset
Value
31–18
Reserved
Reserved
17–16
SOC
Scheduling overrun count
Counts the number of times a scheduling overrun occurs.
This count is incremented even if the host controller driver
has not acknowledged any previous pending scheduling
overrun interrupt.
R
00
15 –4
Reserved
Reserved
3
OCR
Ownership change request
This bit is set by the host controller driver to gain ownership
of the host controller.
OMAP5910 does not support SMI interrupts, so no
ownership change interrupt occurs.
R/W
0
2
BLF
Bulk list filled
The host controller driver must set this bit if it modifies the
bulk list to include new TDs. If HcBulkCurrentED is 0, the
USB host controller does not begin processing bulk list EDs
unless this bit is set. When the USB host controller sees this
bit set and begins processing the bulk list, it clears this bit.
R/W
0
1
CLF
Control list filled
The host controller driver must set this bit if it modifies the
control list to include new TDs. If HcControlHeadED is 0, the
USB host controller does not begin processing control list
EDs unless this bit is set. When the USB host controller sees
this bit set and begins processing the control list, it clears this
bit.
R/W
0
0
HCR
Host controller reset
Write of 0 has no effect.
1: This bit initiates a software reset of the USB host
controller. This transitions the USB host controller to the
USBSuspend state. This resets most USB host controller
OHCI registers. OHCI register accesses must not be
attempted until a read of this register returns a 0. A write of 1
to this bit does not reset the root hub, and does not signal
USB reset to downstream USB functions.
R/W
0