LPC Microcontrollers中的主题 Re: LPC1788 SDRAM GPDMA

LPC1788 SDRAM GPDMA

rafaelzingler — Mon, 29 Apr 2019 21:01:42 GMT

Hi,

I'm trying to use GPDMA M2M transfers using an external SDRAM memory connected to an LPC1788. The idea behind this is to automate copy of data between 2 different buffers (front buffer and back buffer), in a video application. There must be transferred 768000 bytes from one buffer to the other every time the apllication does the "buffer switching". Has anyone did it already? Is it possible? Could anyone post an example on how to configure the hardware? Should I use linked lists to enable transfers of more data?

Thanks in advance.

Re: LPC1788 SDRAM GPDMA

jeremyzhou — Tue, 30 Apr 2019 02:11:00 GMT

Hi Rafael Zingler,

Thank you for your interest in NXP Semiconductor products and
for the opportunity to serve you.
According to your statement, it seems that you want to implement the scatter/gather feature of the GPDMA, is it right?

Have a great day,
TIC

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Re: LPC1788 SDRAM GPDMA

rafaelzingler — Tue, 30 Apr 2019 02:37:54 GMT

Hi.

I'm really not sure about the need of the scatter/gather feature. I have 2

memory areas, each one with 768,000 bytes. The 768,000 bytes in each area

are contiguous. Both areas reside in external SDRAM, and I would like to

use the GPDMA with M2M configuration to copy data from one area to the

other. So, the GPDMA needs to transfer 768,000 bytes each time. On each

pair of transfers, in the first one buffer A need to be the source and

buffer B need to be the destination. In the second one buffer A is the

destination and buffer B is the source.

Thank you very much!!

Em seg, 29 de abr de 2019 23:12, jeremyzhou <admin@community.nxp.com>

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Re: LPC1788 SDRAM GPDMA
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Re: LPC1788 SDRAM GPDMA

jeremyzhou — Sun, 05 May 2019 05:52:23 GMT

Hi Rafael Zingler,

Thanks for your reply.
In my opinion, you can give a try to use the scatter/gather feature to make it.

Have a great day,
TIC

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