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tinyusb
0.4
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tinyusb
0.4
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Highspeed Isochronous Transfer Descriptor (section 3.3) More...
#include <ehci.h>
Data Fields | |
| ehci_link_t | next |
| Word 0: Next Link Pointer. | |
| struct { | |
| volatile uint32_t offset: 12 | |
| This field is a value that is an offset, expressed in bytes, from the beginning of a buffer. | |
| volatile uint32_t page_select: 3 | |
| These bits are set by software to indicate which of the buffer page pointers the offset field in this slot should be concatenated to produce the starting memory address for this transaction. The valid range of values for this field is 0 to 6. | |
| uint32_t int_on_complete: 1 | |
| If this bit is set to a one, it specifies that when this transaction completes, the Host Controller should issue an interrupt at the next interrupt threshold. | |
| volatile uint32_t length: 12 | |
| For an IN, the initial value of the field is the number of bytes the host expects the endpoint to deliver. During the status update, the host controller writes back the number of bytes successfully received. The value in this register is the actual byte count. More... | |
| volatile uint32_t error: 1 | |
| Set to a one by the Host Controller during status update in the case where the host did not receive a valid response from the device (Timeout, CRC, Bad PID, etc.). This bit may only be set for isochronous IN transactions. | |
| volatile uint32_t babble_err: 1 | |
| Set to a 1 by the Host Controller during status update when a babble is detected during the transaction. | |
| volatile uint32_t buffer_err: 1 | |
| Set to a 1 by the Host Controller during status update to indicate that the Host Controller is unable to keep up with the reception of incoming data (overrun) or is unable to supply data fast enough during transmission (underrun). | |
| volatile uint32_t active: 1 | |
| Set to 1 by software to enable the execution of an isochronous transaction by the Host Controller. | |
| } | xact [8] |
| Word 1-8: iTD Transaction Status and Control List. | |
| uint32_t | BufferPointer [7] |
| Word 9-15 Buffer Page Pointer List (Plus) | |
| volatile uint32_t length |
For an IN, the initial value of the field is the number of bytes the host expects the endpoint to deliver. During the status update, the host controller writes back the number of bytes successfully received. The value in this register is the actual byte count.
For an OUT, this field is the number of data bytes the host controller will send during the transaction. The host controller is not required to update this field to reflect the actual number of bytes transferred during the transfer
1.8.6 
