NXP Semiconductors QorIQ LS1012A Reference Manual

Software must not use an FSTN in the asynchronous schedule. An FSTN in theasynchronous schedule results in undefined behavior.Table 32-32. Frame span traversal node structure31 30292827262524232221201918171615 14131211109 8 7 6 5 4 3 2 1 0 offsetNormal path link pointer - Typ T 0x00Back path link pointer - Typ T 0x04NOTEThe host controller performs only read operations to the FSTNdata structure.32.5.7.1 FSTN normal path pointerThe first DWord of an FSTN contains a link pointer to the next schedule object.This object can be of any valid periodic schedule data type. The table below describes theFSTN normal path pointer.Table 32-33. FSTN normal path pointerBits Name Description31-5 NPLP Normal path link pointer. Contains the address of the next data object to be processed in the periodic listand corresponds to memory address signals [31:5], respectively.4-3 - Reserved, should be cleared. These bits must be written as 0s.2-1 Typ Indicates to the host controller whether the item referenced is a iTD/siTD, QH, or FSTN. This allows thehost controller to perform the proper type of processing on the item after it is fetched.00 iTD (isochronous transfer descriptor)01 QH (queue head)10 siTD (split transaction isochronous transfer descriptor)11 FSTN (frame span traversal node)0 T Terminate.0 Link pointer is valid.1 Link pointer field is not valid.32.5.7.2 FSTN back path link pointerThe second DWord of an FSTN node contains a link pointer to a queue head.Chapter 32 Universal Serial Bus Interface 2.0QorIQ LS1012A Reference Manual, Rev. 1, 01/2018NXP Semiconductors 1991