Endpoint Transfer Descriptor (Dtd) - Freescale Semiconductor MPC8313E Family Reference Manual

Table 16-77 describes the multiple mode control fields.
DWord Bits
1 31–0 Setup Buffer 0. This buffer contains bytes 3 to 0 of an incoming setup buffer packet and is written by the
device controller to be read by software.
2 31–0 Setup Buffer 1. This buffer contains bytes 7 to 4 of an incoming setup buffer packet and is written by the
device controller to be read by software.
16.7.2

Endpoint Transfer Descriptor (dTD)

The dTD describes the location and quantity of data to be sent/received for given transfer to the device
controller. The DCD should not attempt to modify any field in an active dTD except the Next Link Pointer,
which should only be modified as described in
Descriptors."
Figure 16-62 shows the endpoint transfer descriptor.
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
0 Total Bytes
Buffer Pointer (Page 0)
Buffer Pointer (Page 1)
Buffer Pointer (Page 2)
Buffer Pointer (Page 3)
Buffer Pointer (Page 4)
1
Device controller read/write; all others read-only.
Table 16-78 describes the next dTD pointer fields.
Bits
31–5 Next transfer element pointer. This field contains the physical memory address of the next dTD to be processed. The
field corresponds to memory address signals [31:5], respectively.
4–1 Reserved, should be cleared. Bits reserved for future use and should be cleared.
0 Terminate (T). 1=pointer is invalid. 0=Pointer is valid (points to a valid Transfer Element Descriptor). This bit indicates
to the Device Controller that there are no more valid entries in the queue.
MPC8313E PowerQUICC II Pro Integrated Processor Family Reference Manual, Rev. 3
Freescale Semiconductor
Table 16-77. Multiple Mode Control
Section 16.8.5, "Managing Transfers with Transfer
15
Next Link Pointer
1
ioc
Figure 16-62. Endpoint Transfer Descriptor (dTD)
Table 16-78. Next dTD Pointer
Description
14 13 12 11 10 9 8
000 MultO 00
0
0000_0000_0000
0000_0000_0000
0000_0000_0000
Description
Universal Serial Bus Interface
7 6 5 4 3 2 1
0000
1
Status
1
Current Offset
1
Frame Number
0 offset
T 0x00
0x04
0x08
0x0C
0x10
0x14
0x18
16-129