Texas Instruments TMS320DM357 用户手册
4.37 Receive CPPI DMA State Word 0 (RCPPIDMASTATEW0)
4.38 Receive CPPI DMA State Word 1 (RCPPIDMASTATEW1)
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Registers
Table 52. Transmit CPPI Completion Pointer (TCPPICOMPPTR) Field Descriptions
Bit
Field
Value
Description
31-2
DESC_ADDR
0-3FFF FFFFh
Descriptor Address
This field contains the 30-bit word aligned pointer of the end of packet descriptor that the
DMA has last processed
DMA has last processed
1
Reserved
0
Reserved
0
WRBK_MODE
Writeback/Compare Mode. This bit controls the action that is to be taken when this location
is written.
is written.
0
Compare Mode. Indicates that the value that is presented on bits 31:2 of the write data
should be compared against the value that is currently contained in bits 31:2 of this location.
If the two match, the interrupt bit corresponding to this Tx Queue should be deasserted.
should be compared against the value that is currently contained in bits 31:2 of this location.
If the two match, the interrupt bit corresponding to this Tx Queue should be deasserted.
1
Writeback Mode. Indicates that the value that is presented on bits 31:2 of the write data
should be written to this location and the interrupt for this Tx Queue should be asserted. This
bit is read as zero.
should be written to this location and the interrupt for this Tx Queue should be asserted. This
bit is read as zero.
The Receive CPPI DMA State Word 0 (RCPPIDMASTATEW0) is shown in
and described in
.
Figure 52. Receive CPPI DMA State Word 0 (RCPPIDMASTATEW0)
31
16
Reserved
R-0
15
8
7
0
Reserved
SOP_BUFFER_OFFSET
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 53. Receive CPPI DMA State Word 0 (RCPPIDMASTATEW0) Field Descriptions
Bit
Field
Value
Description
31-8
Reserved
0-7FFF FFh
Reserved
7-0
SOP_BUFFER_OFFSET
0-FFh
Start of Packet Buffer Offset
Controls how many bytes the Receive DMA will skip at the beginning of the start
of packet buffer before beginning to fill the buffer with receive data. This field is
programmed by the Host software when the channel is set up to facilitate
addition of various protocol encapsulation headers for retransmission of received
packets.
of packet buffer before beginning to fill the buffer with receive data. This field is
programmed by the Host software when the channel is set up to facilitate
addition of various protocol encapsulation headers for retransmission of received
packets.
The Receive CPPI DMA State Word 1 (RCPPIDMASTATEW1) is shown in
and described in
.
SPRUGH3 – November 2008
Universal Serial Bus (USB) Controller
105