* This section describes compile tokens which affect USB driver stack as a whole in the LUFA library.\r
*\r
* <b>USE_RAM_DESCRIPTORS</b> - ( \ref Group_Descriptors ) \n\r
- * Define this token to indicate to the USB driver that device descriptors are stored in RAM, rather than the default of\r
- * the AVR's flash. RAM descriptors may be desirable in applications where speed or minimizing flash usage is more important\r
- * than RAM usage, or applications where the descriptors need to be modified at runtime.\r
+ * Define this token to indicate to the USB driver that all device descriptors are stored in RAM, rather than being located in any one\r
+ * of the AVR's memory spaces. RAM descriptors may be desirable in applications where the descriptors need to be modified at runtime.\r
+ *\r
+ * <b>USE_FLASH_DESCRIPTORS</b> - ( \ref Group_Descriptors ) \n\r
+ * Similar to USE_RAM_DESCRIPTORS, but all descriptors are stored in the AVR's FLASH memory rather than RAM.\r
*\r
* <b>USE_EEPROM_DESCRIPTORS</b> - ( \ref Group_Descriptors ) \n\r
- * Similar to USE_RAM_DESCRIPTORS, but descriptors are stored in the AVR's EEPROM memory rather than RAM.\r
+ * Similar to USE_RAM_DESCRIPTORS, but all descriptors are stored in the AVR's EEPROM memory rather than RAM.\r
*\r
* <b>USE_NONSTANDARD_DESCRIPTOR_NAMES</b> - ( \ref Group_Descriptors ) \n\r
* The USB 2.0 standard gives some rather obscure names for the elements in the standard descriptor types (device, configuration,\r
* defined to a non-zero value instead to give the size in bytes of the control endpoint, to reduce the size of the compiled\r
* binary.\r
*\r
- * <b>USE_SINGLE_DEVICE_CONFIGURATION</b> - ( \ref Group_Device ) \n\r
+ * <b>DEVICE_STATE_AS_GPIOR</b> - ( \ref Group_Device ) \n\r
+ * One of the most frequenty used global variables in the stack is the USB_DeviceState global, which indicates the current state of\r
+ * the Device State Machine. To reduce the amount of code and time required to access and modify this global in an application, this token\r
+ * may be defined to a value between 0 and 2 to fix the state variable into one of the three general purpose IO registers inside the AVR\r
+ * reserved for application use. When defined, the corresponding GPIOR register should not be used within the user application except\r
+ * implicitly via the library APIs.\r
+ *\r
+ * <b>HOST_STATE_AS_GPIOR</b> - ( \ref Group_Host ) \n\r
+ * One of the most frequenty used global variables in the stack is the USB_HostState global, which indicates the current state of\r
+ * the Host State Machine. To reduce the amount of code and time required to access and modify this global in an application, this token\r
+ * may be defined to a value between 0 and 2 to fix the state variable into one of the three general purpose IO registers inside the AVR\r
+ * reserved for application use. When defined, the corresponding GPIOR register should not be used within the user application except\r
+ * implicitly via the library APIs.\r
+ *\r
+ * <b>FIXED_NUM_CONFIGURATIONS</b> - ( \ref Group_Device ) \n\r
* By default, the library determines the number of configurations a USB device supports by reading the device descriptor. This reduces\r
* the amount of configuration required to set up the library, and allows the value to change dynamically (if descriptors are stored in\r
- * EEPROM or RAM rather than flash memory) and reduces code maintenance. However, many USB device projects use only a single configuration.\r
- * Defining this token enables single-configuration mode, reducing the compiled size of the binary at the expense of flexibility.\r
+ * EEPROM or RAM rather than flash memory) and reduces code maintenance. However, this value may be fixed via this token in the project\r
+ * makefile to reduce the compiled size of the binary at the expense of flexibility.\r
*\r
* <b>CONTROL_ONLY_DEVICE</b> \n\r
* In some limited USB device applications, there are no device endpoints other than the control endpoint; i.e. all device communication\r
* by defining this token, reducing the compiled binary size. When removed, the stream functions no longer accept a callback function as\r
* a parameter.\r
*\r
+ * <b>FAST_STREAM_TRANSFERS</b> - ( \ref Group_EndpointPacketManagement , \ref Group_PipePacketManagement )\n\r
+ * By default, streams are transferred internally via a loop, sending or receiving one byte per iteration before checking for a bank full\r
+ * or empty condition. This allows for multiple stream functions to be chained together easily, as there are no alignment issues. However,\r
+ * this can lead to heavy performance penalties in applications where large streams are used frequently. When this compile time option is\r
+ * used, bytes are sent or recevied in groups of 8 bytes at a time increasing performance at the expense of a larger flash memory consumption\r
+ * due to the extra code required to deal with byte alignment.\r
+ *\r
* <b>USB_HOST_TIMEOUT_MS</b> - ( \ref Group_Host ) \n\r
* When a control transfer is initiated in host mode to an attached device, a timeout is used to abort the transfer if the attached\r
* device fails to respond within the timeout period. This token may be defined to a non-zero 16-bit value to set the timeout period for\r
* <b>HOST_DEVICE_SETTLE_DELAY_MS</b> - ( \ref Group_Host ) \n\r
* Some devices require a delay of up to 5 seconds after they are connected to VBUS before the enumeration process can be started, or\r
* they will fail to enumerate correctly. By placing a delay before the enumeration process, it can be ensured that the bus has settled\r
- * back to a known idle state before communications occur with the device. This token may be defined to a non-zero 16-bit value to set\r
- * the device settle period, specified in milliseconds. If not defined, the default value specified in Host.h is used instead.\r
+ * back to a known idle state before communications occur with the device. This token may be defined to a 16-bit value to set the device\r
+ * settle period, specified in milliseconds. If not defined, the default value specified in Host.h is used instead.\r
*\r
* <b>USE_STATIC_OPTIONS</b> - ( \ref Group_USBManagement ) \n\r
* By default, the USB_Init() function accepts dynamic options at runtime to alter the library behaviour, including whether the USB pad\r
* On the smaller USB AVRs, the USB controller lacks VBUS events to determine the physical connection state of the USB bus to a host. In lieu of\r
* VBUS events, the library attempts to determine the connection state via the bus suspension and wake up events instead. This however may be\r
* slightly inaccurate due to the possibility of the host suspending the bus while the device is still connected. If accurate connection status is\r
- * required, the VBUS line of the USB connector should be routed to an AVR pin to detect its level, so that the USB_IsConnected global\r
- * can be accurately set and the USB_Connect and USB_Disconnect events manually raised by the RAISE_EVENT macro. When defined, this token disables\r
- * the library's auto-detection of the connection state by the aforementioned suspension and wake up events.\r
+ * required, the VBUS line of the USB connector should be routed to an AVR pin to detect its level, so that the USB_DeviceState global\r
+ * can be accurately set and the \ref EVENT_USB_Device_Connect() and \ref EVENT_USB_Device_Disconnect() events manually raised by the RAISE_EVENT macro.\r
+ * When defined, this token disables the library's auto-detection of the connection state by the aforementioned suspension and wake up events.\r
*\r
* <b>INTERRUPT_CONTROL_ENDPOINT</b> - ( \ref Group_USBManagement ) \n\r
* Some applications prefer to not call the USB_USBTask() management task reguarly while in device mode, as it can complicate code significantly.\r
projects / pub / lufa.git / blobdiff