Rainbow Electronics DS31256 - Manual (Page 88)

DS31256
88 of 181
Figure 9-1. Receive DMA Operation
Free Data Buffer Address
00h
08h
10h
Free Queue Descriptors
(circular queue)
00h
04h
08h
Done Queue Descriptors
(circular queue)
Open Descriptor Space
Available for Use by the DMA
Data Buffer Address
Unused
Timestamp CH #2
Status
0Ch
Free Data Buffer
(up to 8191 bytes)
Free Data Buffer
(up to 8191 bytes)
First Filled
Data Buffer
for Channel 2
Free Packet Descriptors & Data Buffers
Used Packet Descriptors & Data Buffers
Single Filled
Data Buffer
for Channel 5
Second Filled
Data Buffer
for Channel 2
Last Filled
Data Buffer
for Channel 2
Single Filled
Data Buffer
for Channel 9 dmarbd
unused Free Desc. Ptr.
Free Desc. Ptr.
Free Desc. Ptr.
unused
unused
Free Data Buffer Address
Free Data Buffer Address
Open Descriptor Space
Available for Use by the DMA
# Bytes Next Desc. Ptr.
Data Buffer Address
Timestamp CH #5
Status # Bytes Next Desc. Ptr.
Data Buffer Address
Timestamp CH #2
Status # Bytes Next Desc. Ptr.
Data Buffer Address
Timestamp CH #2
Status # Bytes Next Desc. Ptr.
Data Buffer Address
Timestamp CH #9
Status # Bytes Next Desc. Ptr.
EOF Status CH #5 Desc. Ptr.
EOF Status CH #2 Desc. Ptr.
EOF Status CH #9 Desc. Ptr.
EOF Status CH # Desc. Ptr.