Re: WRITE_PORT_BUFFER_ULONG
- From: davidka@xxxxxxxxxxxxxxxxxxxx ("David Kanz [MSFT]")
- Date: Tue, 10 Oct 2006 00:56:21 GMT
You need to figure out the capabilities of the underlying serial port
hardware first.
WRITE_PORT_BUFFER_ULONG is normally used in a disk driver or ethernet
driver where there is a 32 bit I/O port register on the peripheral that
writing to repeatedly will write consecutive ULONGs to an internal RAM/DMA
buffer on the peripheral.
This sounds like too high speed of an operation for a serial port. Also,
the serial port needs to consider flow control and such.
If the hardware you are using can support such high data-rates, then maybe
the COMMTIMEOUTS need to be reduced using SetCommTimeouts.
David Kanz [MSFT]
This posting is provided "AS IS" with no warranties, and confers no rights.
--------------------
| From: "Telis" <adosis@xxxxxxxxxxxxx>
| Newsgroups: microsoft.public.windowsce.embedded.vc
| Subject: Re: WRITE_PORT_BUFFER_ULONG
| Date: 5 Oct 2006 04:26:35 -0700
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| Thanks Steve for your reply,
| The answer to your question is because either WinCE or my PC104
| processor/Eurotech delays the serial outgoing packet after calling the
| serial WriteFile. I contacted Eurotech and after following their
| suggestions I tried to set the thread priorities higher, using
| Priority256 as 10 in the registry, and also CeSetThreadPriority etc but
| I'm still getting the same results.
| I understand that going through WRITE_PORT_BUFFER_ULONG is maybe worst
| than climbing the Everest, but I'd like to know if there's anybody
| there who went through that and is kind enough to give me some hints.
| If its impossible, then I certainly need to find an alternative way.
|
| still hoping..
| Telis
|
|
| Steve Maillet (eMVP) wrote:
| > >I would like to know if there is any chance to bypass the serial
| > >WriteFile() by using WRITE_PORT_BUFFER_ULONG straight on the serial com
| > >I/O.
| > Ummm, why? The driver will usually do that underneath anyway. It hides
the
| > hardware specifics of where the port is and even if such a thing is even
| > possible given the hardware the driver is for. (It's possible a hardware
| > implementation won't work with that particular function).
| >
| > --
| > Steve Maillet
| > EmbeddedFusion
| > www.EmbeddedFusion.com
| > smaillet at EmbeddedFusion dot com
|
|
.
- References:
- WRITE_PORT_BUFFER_ULONG
- From: Telis
- Re: WRITE_PORT_BUFFER_ULONG
- From: Telis
- WRITE_PORT_BUFFER_ULONG
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