Texas Instruments Tiva TM4C123GH6PM, User Manual

Page: 327 / 352

USB Controller
24.3.1.36 ROM_USBHostPwrConfig
Sets the configuration for USB power fault.
Prototype:
void
ROM_USBHostPwrConfig(uint32_t ui32Base,
uint32_t ui32Flags)
ROM Location:
ROM_APITABLE
is an array of pointers located at
0x0100.0010
.
ROM_USBTABLE
is an array of pointers located at
ROM_APITABLE[16]
.
ROM_USBHostPwrConfig
is a function pointer located at
ROM_USBTABLE[30]
.
Parameters:
ui32Base specifies the USB module base address.
ui32Flags
specifies the configuration of the power fault.
Description:
This function controls how the USB controller uses its external power control pins (USBnPFTL
and USBnEPEN). The flags specify the power fault level sensitivity, the power fault action, and
the power enable level and source.
One of the following can be selected as the power fault level sensitivity:
USB_HOST_PWRFLT_LOW - An external power fault is indicated by the pin being driven
low.
USB_HOST_PWRFLT_HIGH - An external power fault is indicated by the pin being driven
high.
One of the following can be selected as the power fault action:
USB_HOST_PWRFLT_EP_NONE
- No automatic action when power fault detected.
USB_HOST_PWRFLT_EP_TRI - Automatically Tri-state the USBnEPEN pin on a power
fault.
USB_HOST_PWRFLT_EP_LOW - Automatically drive USBnEPEN pin low on a power
fault.
USB_HOST_PWRFLT_EP_HIGH - Automatically drive USBnEPEN pin high on a power
fault.
One of the following can be selected as the power enable level and source:
USB_HOST_PWREN_MAN_LOW - USBEPEN is driven low by the USB controller when
ROM_USBHostPwrEnable() is called.
USB_HOST_PWREN_MAN_HIGH - USBEPEN is driven high by the USB controller when
ROM_USBHostPwrEnable() is called.
USB_HOST_PWREN_AUTOLOW - USBEPEN is driven low by the USB controller auto-
matically if USBOTGSessionRequest() has enabled a session.
USB_HOST_PWREN_AUTOHIGH - USBEPEN is driven high by the USB controller auto-
matically if USBOTGSessionRequest() has enabled a session.
The USB_HOST_PWREN_FILTER flag can be added to enable the VBUS glitch filter, which
ignores small, short drops in VBUS level caused by high power consumption. This is mainly
used to avoid causing VBUS errors caused by devices with high in-rush current.
April 8, 2013 327