Universal Serial Bus Controller User's Guide

4.39 Receive CPPI DMA State Word 2 (RCPPIDMASTATEW2)
4.40 Receive CPPI DMA State Word 3 (RCPPIDMASTATEW3)
www.ti.com Registers
The Receive CPPI DMA State Word 2 (RCPPIDMASTATEW2) is shown in Figure 54 and described in
Table 55 .
Figure 54. Receive CPPI DMA State Word 2 (RCPPIDMASTATEW2)
31 16
SOP_DESCRIPTOR_PTR
R/W-0
15 2 1 0
SOP_DESCRIPTOR_PTR Reserved IN_PACKET
R/W-0 R-0 R/W-0
LEGEND: R/W = Read/Write; R = Read only; - n = value after reset
Table 55. Receive CPPI DMA State Word 2 (RCPPIDMASTATEW2) Field Descriptions
Bit Field Value Description
31-2 SOP_DESCRIPTOR_PTR 0-1FFF FFFFh Start of Packet Buffer Descriptor Pointer
30-bit pointer to 32-bit aligned descriptor which is the first descriptor for the
current packet
1 Reserved 0 Reserved
0 IN_PACKET Flag indicating the DMA is in the middle of processing a packet 0: Not currently
in packet
0 Not currently in packet
1 Currently in packet
The Receive CPPI DMA State Word 3 (RCPPIDMASTATEW3) is shown in Figure 55 and described in
Table 56 .
Figure 55. Receive CPPI DMA State Word 3 (RCPPIDMASTATEW3)
31 16
CURR_DESCRIPTOR_PTR
R/W-0
15 1 0
CURR_DESCRIPTOR_PTR Reserved
R/W-0 R-0
LEGEND: R/W = Read/Write; R = Read only; - n = value after reset
Table 56. Receive CPPI DMA State Word 3 (RCPPIDMASTATEW3) Field Descriptions
Bit Field Value Description
31-2 CURR_DESCRIPTOR_PTR 0-3FFF FFFFh Current Buffer Descriptor Pointer
30-bit pointer to 32-bit aligned descriptor for buffer into which data is currently
being received
1-0 Reserved 0 Reserved
SPRUGH3 – November 2008 Universal Serial Bus (USB) Controller 107
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