Write DMA Registers
BCM5718 Programmer’s Guide
Broadcom
®
January 29, 2016 • 5718-PG108-R
Page 449
Write DMA Registers
All registers reset are core reset unless specified.
Write DMA Mode Register (offset: 0x4C00)
Name
Bits
Access
Default
Value
Description
Reserved
31:30
RO
0
–
Enable FIX for host coalescing
bug
29
RW
0
1: Enable the FIX
0: Disable the FIX
To Fix the bug that device will send out Status
Block before the interrupt message.
(BCM5719/5720 only) WDMA
small packet improvement
disable
28
RW
0
wdma_small_packet_improvement_disable
0: Use new local RRR data instead of fetching
from RBD memory (default enable).
1: Use old implementation to fetch RRR data
from RBD memory.
Reserved
28:19
RO
0
–
Swap Test Enable
18
RW
0
When this bit is set, swap test mode will be
enabled and bits 17 to 12 can be used to test
different byte/word swap settings.
HC Byte Swap
17
RW
0
Byte swap control for status words.
HC Word Swap
16
RW
0
Word swap control for status words.
BD Byte Swap
15
RW
0
Byte swap control for return BDs.
BD Word Swap
14
RW
0
Word swap control for return BDs
Data Byte Swap
13
RW
0
Byte swap control for data.
Data Word Swap
12
RW
0
Word swap control for data.
Software Byte Swap Control
11
RW
0
To override byte enables with all 1's.
Receive Accelerate mode
10
RW
0
The write DMA-to-PCI request length is the
available data size in the PCI RX FIFO.
Set to 1: The write DMA-to-PCI request length is
the maximum length of the current transaction,
regardless of the available data size in PCI RX
FIFO. This mode cannot be used in slow core
clock environment. Disable this mode before
switching to slow core clock mode.
Write DMA Local Memory
9
RW
0
Attention Enable. Enable Write DMA Local
Memory Read Longer Than DMA Length
Attention.
Write DMA PCI FIFO Overwrite
Attention Enable
8
RW
0
Enable Write DMA PCI FIFO Overwrite Attention
(PCI write longer than DMA length).
Write DMA PCI FIFO Underrun
Attention Enable
7
RW
0
Enable Write DMA PCI FIFO Underrun Attention.