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Re: serial port ARM e7t problem
- From: Roland Caßebohm <roland dot cassebohm at visionsystems dot de>
- To: "Ravi Kumar B S" <ravikbs at mindtree dot com>, "Vinayak P Risbud" <vinayak at multitech dot co dot in>, "Ecos-Discuss" <ecos-discuss at sources dot redhat dot com>
- Date: Wed, 17 Jul 2002 10:11:05 +0200
- Subject: Re: [ECOS] serial port ARM e7t problem
- References: <E125980C421DFD4DA0B80D55DB1EDA58980461@mtv01ex01.mindtree.com>
On Wednesday, 17. July 2002 06:26, Ravi Kumar B S wrote:
> The Samsung microcontroller has a DMA controller with it. the UART can be
> configured to work along with the UART chip. This is called DMA mode of the
> UART chip. With this you can configure to get the interrupt after certian
> number of bytes are received instead of single byte interrupt.
Has anybody tried to do this?
I thinked about it, but I haven't found a way to get an interrupt after a
timeout like a FIFO does. A UART with FIFO generates an interrupt after
reaching the triggerlevel or if it received less characters after an timeout.
Without something like this I will never notify if there are characters but
the DMA buffer isn't full.
Although there is nothing like a triggerlevel. If the UART gets the last
character fitting in the DMA-Buffer the interrupt happens and I have to copy
the buffer and restart the DMA before the next character is coming.
So I have the same chance to loose a character.
Roland
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