Rainbow Electronics DS3134 - Manual (Page 124)

DS3134
124 of 203
Transmit DMA Memory Organization Figure 8.2.1B
Free Data Buffer Space
Transmit Pending Queue Descriptors:
Contains Index Pointers to Packet Descriptors
of Queued Data Buffers that are Ready
to be Transmitted
Pending Queue Base Address (32)
Pending Queue End Address (16)
Pending Queue Host Write Pointer (16)
Pending Queue DMA Read Pointer (16)
Up to 64K dwords
Free Queue Descriptors Allowed
Transmit Done Queue Descriptors:
Contains Index Pointers to Packet Descriptors
of Data Buffers that have been Transmitted
Done Queue Base Address (32)
Done Queue End Address (16)
Done Queue DMA Write Pointer (16)
Done Queue Host Read Pointer (16)
Up to 64K dwords
Done Queue Descriptors Allowed
Transmit Packet Descriptors:
Contains 32-Bit Addresses
to Data Buffers as well as
Status/Control Information and
Links to Other Packet Descriptors
Descriptor Base Address (32)
Up to 64K Quad dwords
Descriptors Allowed
Used Data Buffer Space
Main Offboard Memory
(32-Bit Address Space) Internal Chateau Registers
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