RDMA Registers
BCM5718 Programmer’s Guide
Broadcom
®
January 29, 2016 • 5718-PG108-R
Page 440
BD Read DMA Mode Register (offset: 0x4A00)
Name
Bits
Access
Default
Value
Description
Reserved
31:29
RO
0
–
Hardware IPv6 Post-DMA
Processing Enable
28
RO
0
Enables hardware processing of LSO IPv6
packets. This bit has no effect on Post-DMA
processing of IPv4 packets.
Hardware IPv4 Post-DMA
Processing Enable
27
RO
0
Enables hardware processing of LSO IPv4
packets. This bit has no effect on Post-DMA
processing of IPv6 packets.
Post-DMA Debug Enable
26
RO
0
When this bit is set, the Send Data Completion
State Machine will be halted if the Post-DMA bit
of the Send BD is set.
Address Overflow Error
Logging Enable
25
RO
0
This bit when set, enables the address overflow
error to be generated when the DMA Read
Engine performs a DMA operation that crosses a
4G boundary. This error is reported in bit 3 of the
DMA Read Status Register. Subsequently, this
will generate an internal event to interrupt the
internal CPU and the DMA Read Engine will lock
up after detecting this error. So it is
recommended that this bit should not be set by
firmware or software.
1: Enable Address Overflow Error Logging
0: Disable Address Overflow Error Logging.
Reserved
24:18
RO
0
–
PCI Request Burst Length
17:16
RO
0
• 00 = 128 bytes
• 01 = 256 bytes
• 10 = 512 bytes
• 11 = 4096 bytes
Note:
The actual size of the resulting PCIe
memory read transaction may be further limited
by the PCIe Maximum Read Request Size
(MRRS) field of the PCIe Device Status Control
Register (0xB4).
Reserved
15:11
RO
0
–
Read DMA PCI-X Split
Transaction Timeout Expired
Attention Enable
10
RO
0
Enable read DMA PCI-X split transaction timeout
expired attention.
Read DMA Local Memory
Write Longer Than DMA
Length Attention Enable
9
RO
0
Enable Read DMA Local Memory Write Longer
Than DMA Length Attention.
Read DMA PCI FIFO Overread
Attention Enable
8
RO
0
Enable Read DMA PCI FIFO Overread Attention
(PCI read longer than DMA length.)
Read DMA PCI FIFO Underrun
Attention Enable
7
RO
0
Enable Read DMA PCI FIFO Underrun Attention.
Read DMA PCI FIFO Overrun
Attention Enable
6
RO
0
Enable Read DMA PCI FIFO Overrun Attention.