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15.10.8 Next Link Pointer<br />

DWORD0 of a siTD is a pointer to the next schedule data structure.<br />

Table 15‐24: Next Link Pointer<br />

Bits Description<br />

Chapter 15: USB Host, Device, and OTG Controllers<br />

31:5 Next Link Pointer<br />

This field contains the address of the next data object to be processed in the periodic<br />

list and corresponds to memory address signals [31:5], respectively.<br />

2:1 Queue Head Type (Typ)<br />

This field indicates to the Host Controller whether the item referenced is an iTD, siTD<br />

or a QH. This allows the Host Controller to perform the proper type of processing on<br />

the item after it is fetched. Value encodings are:<br />

• 00b: iTD (isochronous transfer descriptor)<br />

• 01b: QH (queue head)<br />

• 10b: siTD (split transaction isochronous transfer descriptor)<br />

• 11b: FSTN (frame span traversal node)<br />

0 Terminate bit (T)<br />

• 1b: Link Pointer field is not valid<br />

• 0b: Link Pointer field is valid<br />

<strong>Zynq</strong>‐<strong>7000</strong> EPP Technical Reference Manual www.xilinx.com 349<br />

UG585 (v1.2) August 8, 2012

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