Re: PCI Express Transfer Problems.

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SlowTransfer <SlowTransfer@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:

You mean there is nothing before i change my design.

I mean there is nothing you can do, period. When you write to memory from
the CPU, you write one dword at a time. The PCI Express root complex does
not know that you are writing the first word of a block, so it doesn't
start a burst. How could it possibly know that?

The only way for you to get a burst is to have your device be bus master.

Yesterday I googled Intel site also, And I found something.
Unfortunally I couldn't understand what it means.

There was a word "Intel will not allow non cashed memory to be transfered in
burst"

So I created a variable which has to be transfered like below.
pkMem = ExAllocatePoolWithQuota(NonPagedPoolCacheAligned,
pIoBuffer->unData*4);

Do you know if it is that he wants?

If your device does bus master DMA, then you can force a burst transfer. If
you are just doing normal memory writes, then it will not.
--
Tim Roberts, timr@xxxxxxxxx
Providenza & Boekelheide, Inc.
.

Relevant Pages

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    (microsoft.public.development.device.drivers)
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