DMA with powerspan II -Fpga card

Do you have a question? Post it now! No Registration Necessary

Translate This Thread From English to

Threaded View
I had posted earlier my issues with Fpga card.

http://groups.google.com/group/comp.arch.fpga/browse_thread/thread/73534630e805751a/21f880630f20ca74?q=fpga+pci&rnum=1#21f880630f20ca74

The  AMIRIX fpga card uses powerspan II pci bus switch fro Tundra. The
powerpc inside teh fpga has linux running..I have some data in my PLB
master/slave module which has to be transferred to the host pc. So I
was suggested to llok into DMA transfer part. I went through the
powerspan II manual . It doesnt provide the details of data cycle for
the DMA . i.e it only says to write the DMA configuration registers
with the source address , destination address... and then raisethe go
signal. Now my problem is that the source address  needs to be the
on-board RAM address. I dont want to use the onboard RAM.I dont want to
use the powerpc either. I wanted to write a module in vhdl to do the
confguration adn the forward the data to the bridge. I dont know
whether this is possible. I

 I dont have experience in this field. How can I do a transfer of data
from my master/slave module to the host computer?
Is there a way ?
Thanks,
Nitesh


Re: DMA with powerspan II -Fpga card
Nitesh

Because all the addresses on the PCI bus are set by a mixture of card
requirements and software allocation during PCI configuration you will need
software/driver to read the allocation and give the relevant details to your
card for the DMA transfer.

John Adair
Enterpoint Ltd. - Home of Raggedstone1. The Low Cost Spartan-3 PCI
Development Board.
http://www.enterpoint.co.uk


Quoted text here. Click to load it
http://groups.google.com/group/comp.arch.fpga/browse_thread/thread/73534630e805751a/21f880630f20ca74?q=fpga+pci&rnum=1#21f880630f20ca74
Quoted text here. Click to load it



Re: DMA with powerspan II -Fpga card
I have started with the driver on the host side but the thing is I am
still not cear about some things. I have access to the config registers
from the host side. I also can initiate a data transfer from the host
side and read data from the on-board RAM. I also have an option of
configuring from the Processor bus side( interfaced with fpga). but I
dont know how to give data to the pci bridge. i.e how to initiate a
transfer from inside the fpga without using the on-board RAM or powerpc
in the tranfer.The user manual says only how to configure i.e give the
start address( source address in the ram ) , size of data and the
destination address. It doesnt  tell how to go about if i have to send
data without using the RAM, the timing  diagrams.
Thanks,
Nitesh


Re: DMA with powerspan II -Fpga card
I am working on drivers n the host side. I wasnt clear about few
things.  I can configure the bridge from the fpga side over the
processor bus. In the manual its not stated as to how to do the data
transfer without using the on-board RAM. It only specifies how to
configure the bridge for the DMA transfer (with initiation fromthe fpga
side ) i.e to specify the start address on the on-board ram ,
destination address and the size. How do I go about tranferring the
data without using the on-board external RAM.
Is it possible?
Thanks,
Nitesh


Re: DMA with powerspan II -Fpga card
Nitesh

As I thing Brian said you need to look at the chip specification. Usually
you will find a register/s location at a particular offset/s from the BAR
base address for these kind of DMA transfers but I don't have a lot recent
PLX experience to expand on that.

John Adair
Enterpoint Ltd. - Home of Broaddown2. The Ultimate Spartan3 Development
Board.
http://www.enterpoint.co.uk

Quoted text here. Click to load it



Site Timeline