![Intel IXP45X Скачать руководство пользователя страница 572](http://html1.mh-extra.com/html/intel/ixp45x/ixp45x_developers-manual_2073092572.webp)
Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors—PCI Controller
Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
Develepor’s Manual
August 2006
572
Order Number: 306262-004US
10.5.3.22 AHB-to-PCI DMA Length Register 1
10.5.3.23 PCI-to-AHB DMA AHB Address Register 0
Register Name:
pci_atpdma1_length
Block
Base Address:
0xC00000
Offset Address
0x54
Reset Value
0x00000000
Register Description:
Provides word count and control for AHB-to-PCI DMA transfers.
Paired with pci_atpdma0_length to allow buffering of DMA transfer
requests.
Access:
(See below.)
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
EN (Rsvd) DS
(Reserved)
wordcount
Register
pci_atpdma1_length
Bits
Name
Description
Reset
Value
PCI
Access
AHB
Access
31
EN
Channel enable. When set to a 1, executes a DMA transfer if wordcount is
nonzero. When 0, the channel is disabled. Hardware clears this bit when
the DMA transfer is complete.
0
RO
RW
30:2
9
reserved
Reserved. Read as 0.
00
RO
RO
28
DS
Data Swap indicator. When set to a 1, data from the AHB bus is byte
swapped before being sent to the PCI bus. When 0, no swapping is done.
0
RO
RW
27:1
6
reserved
Reserved. Read as 0.
0x000
RO
RO
15:0
wordcount
Number of words to transfer.
0x0000
RO
RW
Register Name:
pci_ptadma0_ahbaddr
Block
Base Address:
0xC00000
Offset Address
0x58
Reset Value
0x00000000
Register Description:
Destination address on the AHB bus for PCI-to-AHB DMA transfers.
Paired with pci_ptadma1_ahbaddr to allow buffering of DMA
transfer requests.
Access:
(See below.)
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
address
0
0
Register
pci_ptadma0_ahbaddr
Bits
Name
Description
Reset
Value
PCI
Access
AHB
Access
31:2
address
AHB word address
0x00000000
RO
RW
1:0
Lower AHB address bits hard-wired to zero.
00
RO
RO