MCUXpresso SDK中的主题 LPC546xx SPI SSEL deasserts problem

LPC546xx SPI SSEL deasserts problem

sharads — Tue, 27 Aug 2019 06:21:32 GMT

I am using LPC54606 interfacing ADS8668 over SPI. Flexcomm2 (PIO1_23 to PIO1_26) is being used for the same with SSEL0. I am using MCUXpresso IDE and SPI driver provided in SDK.

I observed that even after transmit is over CS/SSEL0 pin remains low. (SSEL0 pin remains low all the time).

Due to this ADC is not able to start the conversion and so on as it requires CS to go from HIGH to LOW.

Please suggest how can CS/SSEL0 deasserts itself when there is not data transfer over SPI.

Re: LPC546xx SPI SSEL deasserts problem

Alice_Yang — Wed, 28 Aug 2019 08:06:14 GMT

Hello Sharad Shinde ,

We need to set the End of Transfer (EOT) to 1 in SPI FIFOWR register.This piece of data is treated as the end of a transfer. SSEL will be deasserted at the end of this piece of data.

You can find the code in SDK SPI demo:

Hope it helps,

Have a great day,
TIC

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Re: LPC546xx SPI SSEL deasserts problem

sharads — Thu, 29 Aug 2019 10:17:23 GMT

Thanks you very much Alice_yang.

Yes, I did the changes as per your suggestion and it worked for me.

Great....

Regards,

Sharad

Re: LPC546xx SPI SSEL deasserts problem

Alice_Yang — Fri, 30 Aug 2019 08:31:43 GMT

OK, welcome!

Have a great day,
TIC

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