MEDIATEK Ralink MT7620 - Page 208

PGMT7620_V.1.0_040503
Page 208 of 523
MT7620 PROGRAMMING GUIDE
Integrated 802.11n MAC/BBP and 2.4 GHz RF/FEM Router-on-a-Chip
2.19.7.1 PDMA Rx Field Descriptions
Bit
Name
Description
DWORD0
31:0
SDP0
Segment Data Pointer 0 for header (if HP_SEP_EN = 1) or the whole packet (if HP_SEP_EN =
0).
DWORD1
31
DDONE
DMA Done: Indicates DMA has received the segments pointed to by this Rx descriptor.
30
LS0
Last Segment0: Data pointed to by SDP0 is the last segment.
29:1
6
SDL0
Segment Data Length0: Segment data length for the data pointed to by SDP0.
15
0
Reserved
14
1
Reserved
13:0
SDL1
Segment Data Length1: Segment data length for the data pointed to by SDP1.
DWORD2
31:0
SDP1
Segment Data Pointer1 for payload (if HP_SEG_LEN! = 0), or RXWI + Packet Length (if
HP_SEG_LEN! = 0)
DWORD3 (TXINFO)
31
0
Reserved
30
0
Reserved
29
0
Reserved
28
0
Reserved
27
0
Reserved
26:22
UDF
User defined field (when SP = 3’d6 from CPU port)
27:22
PKT
_INFO
Packet information
Bit[5]: IPv6 packet
Bit[4]: IPv4 packet
Bit[3]: IPV4 checksum error
Bit[2]: TCP packet with ACK flag
Bit[1]: L4 TCP or UDP packet without fragmented flag
Bit[0]: L4 checksum error
21:19
SP
GSW source port
18:14
CRSN
PPE to CPU reason
13:0
PPE
_Entry
PPE Entry number
14’h3FFF: Invalid entry