topic Re: Lpc 824 DMA to GPIO in LPC Microcontrollers

Lpc 824 DMA to GPIO

tvrklejelani — Mon, 05 Dec 2016 13:19:29 GMT

Hi,

i have problems driving lpc gpio port using dma. When i write with dma to any ram adress everything works fine, but when i write to any of registers associated with gpio nothing happens.

My question is... Can 824 use dma to write to gpio.

Based on block diagram of 824, GPIO is connected to ARM M0+ but not to AHB..is this true?

Thx.

Re: Lpc 824 DMA to GPIO

jeremyzhou — Fri, 09 Dec 2016 01:23:51 GMT

Hi Tvrkle JElani ,

Thank you for your interest in NXP Semiconductor products and the opportunity to serve you.

In my opinion, the GPIO is connected to the APB bus, and it can work with the DMA engine.

Hope it helps.
Have a great day,
Ping

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Re: Lpc 824 DMA to GPIO

javiervallori — Mon, 20 Apr 2020 12:08:11 GMT

Did you finally find a solution? I'm having the same problem with a LPC11

Re: Lpc 824 DMA to GPIO

tvrklejelani — Tue, 21 Apr 2020 08:06:42 GMT

Hi, it was a couple of years now, but for 824 it can't use DMA to access gpio, i was always getting dma erros.

And reason is that GPIO is "tightly" coupled to core.

If your LPC has same architecture as on picture above, than i think it can not work.

But if GPIO is connected to AHB bus and DMA is connected to it it might work.

Does that uC has DMA?

BR/Tvrtko

Re: Lpc 824 DMA to GPIO

javiervallori — Wed, 22 Apr 2020 09:06:32 GMT

Thank you! the uC has a DMA, and the GPIO seems to be connect to the AHB. But for some reason, setting DMA destination address to the GPIO has no effect.