查看“OTG internal peripheral”的源代码

==Article purpose==
The purpose of this article is to
* briefly introduce the OTG peripheral and its main features
* indicate the level of security supported by this hardware block
* explain how it can be allocated to the three runtime contexts and linked to the corresponding software components
* explain, when needed, how to configure the OTG peripheral.

==Peripheral overview==
The '''OTG''' peripheral is used to interconnect other systems with STM32 MPU devices, using USB standard.

===Features===
The '''OTG''' peripheral is a USB Dual-Role Device (DRD) controller that supports both device and host functions.<br>
In Host mode, it supports high-speed (480 Mbit/s), full-speed (12 Mbit/s) and low-speed (1.5 Mbit/s).<br>
In Peripheral mode, high-speed and full-speed are supported, not low-speed.<br>
The '''OTG''' peripheral embeds a full-speed PHY and supports a UTMI interface connected to [[USBPHYC internal peripheral|internal HS PHY]].

The '''OTG''' peripheral is fully compliant with
* ''On-The-Go and Embedded Host Supplement to the USB Revision 2.0 Specification''<ref name="otg_specification">[http://www.usb.org/developers/onthego/USB_OTG_and_EH_2-0.pdf On-The-Go and Embedded Host Supplement to the USB Revision 2.0 Specification]</ref>, Revision 2.0, May 8, 2009 
* ''Universal Serial Bus Revision 2.0 Specification''<ref name="usb2_specification">[http://www.usb.org/developers/docs/usb20_docs Universal Serial Bus Revision 2.0 Specification]</ref>, Revision 2.0, April 27, 2000
* ''USB 2.0 Link Power Management Addendum Engineering Change Notice to the USB 2.0 specification''<ref name="lpm_addendum">[http://www.usb.org/developers/docs/usb20_docs ECN USB 2.0 Link Power Management Addendum]</ref>, July 16, 2007
* ''USB 2.0 Transceiver Macrocell Interface (UTMI) Specification''<ref name="utmi_specification">[https://www.intel.com/content/www/us/en/io/universal-serial-bus/usb2-transceiver-macrocell-interface-specification.html USB 2.0 Transceiver Macrocell Interface (UTMI) Specification]</ref>, Version 1.05, March 29, 2001
* ''UTMI+ Specification''<ref name="utmi+_specification">[https://www.nxp.com/docs/en/brochure/UTMI-PLUS-SPECIFICATION.pdf UTMI+ Specification]</ref>, Revision 1.0, February 25, 2004

Refer to [[STM32MP15 resources#Reference manuals|STM32MP15 reference manuals]] for the complete hardware feature list, and to the software components (introduced below) to know which features are supported.

===Security support===
The '''OTG''' peripheral is a '''non-secure''' peripheral.

==Peripheral usage and associated software==
===Boot time===
The OTG peripheral is used by [[STM32MP15 ROM code overview|ROM code]], [[Boot chain overview|FSBL]] and [[Boot chain overview|SSBL]] in device mode (DFU) to support serial boot for flash programming with [[STM32CubeProgrammer]].<br>
The [[Boot chain overview|SSBL]] can use it in host mode (mass storage), for instance to boot on a kernel stored on a USB key, or after a kernel panic to perform the crash dump saving to the USB key.

===Runtime===
====Overview====
The OTG peripheral can be allocated to the Arm<sup>&reg;</sup> Cortex<sup>&reg;</sup>-A7 non-secure core to be used under Linux<sup>&reg;</sup> with [[USB overview | USB framework]].

====Software frameworks====
{{:Internal_peripherals_software_table_template}}
 | High speed interface
 | [[OTG internal peripheral|OTG (USB OTG)]]
 | 
 | [[USB overview | Linux USB framework]]
 | 
 |
 |-
 |}

====Peripheral configuration====
The configuration is applied by the firmware running in the context to which the peripheral is assigned. The configuration by itself can be performed via the [[STM32CubeMX]] tool for all internal peripherals. It can then be manually completed (especially for external peripherals) according to the information given in the corresponding software framework article.

For Linux kernel configuration, please refer to [[OTG device tree configuration|OTG device tree configuration]].

====Peripheral assignment====
{{:Internal_peripherals_assignment_table_template}}
<onlyinclude>
 | rowspan="1" | High speed interface
 | rowspan="1" | [[OTG internal peripheral|OTG (USB OTG)]]
 | OTG (USB OTG)
 | 
 | <span title="assignable peripheral" style="font-size:21px">☐</span>
 |
 |
 |-
</onlyinclude>
 |}

==References==
<references/>

<noinclude>
[[Category:High speed interface peripherals]]
{{PublicationRequestId | 8439 | 2018-09-20 | BrunoB}}
{{ArticleBasedOnModel | Internal peripheral article model}}
</noinclude>