Defines | |
#define | USB_STREAM_TIMEOUT_MS 100 |
Enumerations | |
enum | USB_Modes_t { USB_MODE_None = 0, USB_MODE_Device = 1, USB_MODE_Host = 2, USB_MODE_UID = 3 } |
Functions | |
void | USB_USBTask (void) |
static bool | USB_VBUS_GetStatus (void) ATTR_WARN_UNUSED_RESULT ATTR_ALWAYS_INLINE |
static void | USB_Detach (void) ATTR_ALWAYS_INLINE |
static void | USB_Attach (void) ATTR_ALWAYS_INLINE |
void | USB_Init (const uint8_t Mode, const uint8_t Options) |
void | USB_ShutDown (void) |
void | USB_ResetInterface (void) |
Variables | |
volatile bool | USB_IsInitialized |
USB_Request_Header_t | USB_ControlRequest |
volatile uint8_t | USB_CurrentMode |
volatile uint8_t | USB_Options |
USB Controller Option Masks | |
#define | USB_OPT_REG_DISABLED (1 << 1) |
#define | USB_OPT_REG_ENABLED (0 << 1) |
#define | USB_OPT_MANUAL_PLL (1 << 2) |
#define | USB_OPT_AUTO_PLL (0 << 2) |
Endpoint/Pipe Type Masks | |
#define | EP_TYPE_CONTROL 0x00 |
#define | EP_TYPE_ISOCHRONOUS 0x01 |
#define | EP_TYPE_BULK 0x02 |
#define | EP_TYPE_INTERRUPT 0x03 |
Functions, macros, variables, enums and types related to the setup and management of the USB interface.
#define EP_TYPE_BULK 0x02 |
Mask for a BULK type endpoint or pipe.
#define EP_TYPE_CONTROL 0x00 |
Mask for a CONTROL type endpoint or pipe.
#define EP_TYPE_INTERRUPT 0x03 |
Mask for an INTERRUPT type endpoint or pipe.
#define EP_TYPE_ISOCHRONOUS 0x01 |
Mask for an ISOCHRONOUS type endpoint or pipe.
#define USB_OPT_AUTO_PLL (0 << 2) |
Automatic PLL control option mask for USB_Init(). This indicates to the library that the library should take full responsibility for controlling the AVR's PLL (used to generate the high frequency clock that the USB controller requires) and ensuring that it is locked at the correct frequency for USB operations.
#define USB_OPT_MANUAL_PLL (1 << 2) |
Manual PLL control option mask for USB_Init(). This indicates to the library that the user application will take full responsibility for controlling the AVR's PLL (used to generate the high frequency clock that the USB controller requires) and ensuring that it is locked at the correct frequency for USB operations.
#define USB_OPT_REG_DISABLED (1 << 1) |
Regulator disable option mask for USB_Init(). This indicates that the internal 3.3V USB data pad regulator should be enabled to regulate the data pin voltages to within the USB standard.
#define USB_OPT_REG_ENABLED (0 << 1) |
Regulator enable option mask for USB_Init(). This indicates that the internal 3.3V USB data pad regulator should be disabled and the AVR's VCC level used for the data pads.
#define USB_STREAM_TIMEOUT_MS 100 |
Constant for the maximum software timeout period of the USB data stream transfer functions (both control and standard) when in either device or host mode. If the next packet of a stream is not received or acknowledged within this time period, the stream function will fail.
This value may be overridden in the user project makefile as the value of the USB_STREAM_TIMEOUT_MS token, and passed to the compiler using the -D switch.
enum USB_Modes_t |
Enum for the possible USB controller modes, for initialization via USB_Init() and indication back to the user application via USB_CurrentMode.
static void USB_Attach | ( | void | ) | [inline, static] |
Attaches the device to the USB bus. This announces the device's presence to any attached USB host, starting the enumeration process. If no host is present, attaching the device will allow for enumeration once a host is connected to the device.
This is inexplicably also required for proper operation while in host mode, to enable the attachment of a device to the host. This is despite the bit being located in the device-mode register and despite the datasheet making no mention of its requirement in host mode.
static void USB_Detach | ( | void | ) | [inline, static] |
Detaches the device from the USB bus. This has the effect of removing the device from any attached host, ceasing USB communications. If no host is present, this prevents any host from enumerating the device once attached until USB_Attach() is called.
void USB_Init | ( | const uint8_t | Mode, |
const uint8_t | Options | ||
) |
Main function to initialize and start the USB interface. Once active, the USB interface will allow for device connection to a host when in device mode, or for device enumeration while in host mode.
As the USB library relies on interrupts for the device and host mode enumeration processes, the user must enable global interrupts before or shortly after this function is called. In device mode, interrupts must be enabled within 500ms of this function being called to ensure that the host does not time out whilst enumerating the device. In host mode, interrupts may be enabled at the application's leisure however enumeration will not begin of an attached device until after this has occurred.
Calling this function when the USB interface is already initialized will cause a complete USB interface reset and re-enumeration.
[in] | Mode | This is a mask indicating what mode the USB interface is to be initialized to, a value from the USB_Modes_t enum. |
[in] | Options | Mask indicating the options which should be used when initializing the USB interface to control the USB interface's behaviour. This should be comprised of a USB_OPT_REG_* mask to control the regulator, a USB_OPT_*_PLL mask to control the PLL, and a USB_DEVICE_OPT_* mask (when the device mode is enabled) to set the device mode speed. |
void USB_ResetInterface | ( | void | ) |
Resets the interface, when already initialized. This will re-enumerate the device if already connected to a host, or re-enumerate an already attached device when in host mode.
void USB_ShutDown | ( | void | ) |
Shuts down the USB interface. This turns off the USB interface after deallocating all USB FIFO memory, endpoints and pipes. When turned off, no USB functionality can be used until the interface is restarted with the USB_Init() function.
void USB_USBTask | ( | void | ) |
This is the main USB management task. The USB driver requires this task to be executed continuously when the USB system is active (device attached in host mode, or attached to a host in device mode) in order to manage USB communications. This task may be executed inside an RTOS, fast timer ISR or the main user application loop.
The USB task must be serviced within 30ms while in device mode, or within 1ms while in host mode. The task may be serviced at all times, or (for minimum CPU consumption):
If in device mode (only), the control endpoint can instead be managed via interrupts entirely by the library by defining the INTERRUPT_CONTROL_ENDPOINT token and passing it to the compiler via the -D switch.
static bool USB_VBUS_GetStatus | ( | void | ) | [inline, static] |
Returns boolean true if the VBUS line is currently high (i.e. the USB host is supplying power), otherwise returns false.
Structure containing the last received Control request when in Device mode (for use in user-applications inside of the EVENT_USB_Device_ControlRequest() event, or for filling up with a control request to issue when in Host mode before calling USB_Host_SendControlRequest().
volatile uint8_t USB_CurrentMode |
Indicates the mode that the USB interface is currently initialized to, a value from the USB_Modes_t enum.
volatile bool USB_IsInitialized |
Indicates if the USB interface is currently initialized but not necessarily connected to a host or device (i.e. if USB_Init() has been run). If this is false, all other library globals related to the USB driver are invalid.
volatile uint8_t USB_Options |
Indicates the current USB options that the USB interface was initialized with when USB_Init() was called. This value will be one of the USB_MODE_* masks defined elsewhere in this module.