Freescale Semiconductor MCF54455 Reference Manual page 260

See Section 10.5.2.2, "Endpoint Transfer Descriptor (dTD),"
10.5.2.1.4 Setup Buffer (Offset = 0x28–0x2C)
The set-up buffer is dedicated storage for the 8-byte data that follows a set-up PID. Refer to
Section 10.5.3.4.4, "Control Endpoint
buffer
Each endpoint has a TX and an RX dQH associated with it, and only the RX
queue head receives setup data packets.
longword Field
1 31–0
Setup Buffer 0
2 31–0
Setup Buffer 1
10.5.2.2 Endpoint Transfer Descriptor (dTD)
The dTD describes to the device controller the location and quantity of data sent/received for a given
transfer. The DCD software should not attempt to modify any field in an active dTD except the next dTD
pointer, which must be modified only as described in
Descriptors."
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)
Device controller read/write; all others read-only.
10.5.2.2.1 Next dTD Pointer (Offset = 0x0)
The next dTD pointer is used to point the device controller to the next dTD in the linked list.
Freescale Semiconductor
Operation" for information on the procedure for reading the setup
Table 10-46. Multiple Mode Control
Setup Buffer 0. This buffer contains bytes 3 to 0 of an incoming setup buffer packet and is written
by the device controller software reads.
Setup Buffer 1. This buffer contains bytes 7 to 4 of an incoming setup buffer packet and is written
by the device controller software reads.
Next dTD Pointer
Figure 10-42. Endpoint Transfer Descriptor (dTD)
Universal Serial Bus Interface – On-The-Go Module
for a description of the overlay fields.
NOTE
Description
Section 10.5.3.6, "Managing Transfers with Transfer
15 14 13 12 11 10 9 8
ioc 0 0 0 MultO 0 0
0
0 0 0 0 0 0 0 0 0 0 0 0 0x10
0 0 0 0 0 0 0 0 0 0 0 0 0x14
0 0 0 0 0 0 0 0 0 0 0 0 0x18
7 6 5 4 3 2 1 0
0 0 0 0 T 0x00
Status
Current Offset
Frame Number
offset
0x04
0x08
0x0C
10-53