Having Problem in Multiple Slaves to LPC1768 SPI

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Having Problem in Multiple Slaves to LPC1768 SPI

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nisargnyk
Contributor I

I had attached multiple #CS5463 with #LPC1768, through internal #SPI, if I connect single CS5463 i get exact readings, but when i connect multiple CS5463 with SSEL to other port pins i am not getting any readings from the CS5463 IC register, So please help me out...

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kerryzhou
NXP TechSupport
NXP TechSupport

Hi Nisarg Nayak,

     Thank you for your interest in NXP LPC product, I would like to provide service for you.

     Just one SPI slave CS5463  to LPC1768, it works, but use two or more CS5463 as SPI slave to LPC1768, it can't work.

     Do you use mulitple SSEL pin as the slave select pin?  Different SPI slave need to use different SSEL pin.

     When one SPI slave is select, the other SSEL must be high, just don't select the other SPI slave.

     If you already do it, please use the logic analyzer to check the SPI bus: MISO, MOSI, SCLK, SSELn, SSELn is the mutiple SPI slave node select pin.

     Check the SPI bus wave will be more easy to find the problem.

    After you check the SPI bus wave, please also share the wave to analysis.

    You can also get the one slave mode SPI bus wave, just used to compare with the multiple situation bus wave


Have a great day,
Kerry

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kerryzhou
NXP TechSupport
NXP TechSupport

Hi Nisarg Nayak,

     Thank you for your interest in NXP LPC product, I would like to provide service for you.

     Just one SPI slave CS5463  to LPC1768, it works, but use two or more CS5463 as SPI slave to LPC1768, it can't work.

     Do you use mulitple SSEL pin as the slave select pin?  Different SPI slave need to use different SSEL pin.

     When one SPI slave is select, the other SSEL must be high, just don't select the other SPI slave.

     If you already do it, please use the logic analyzer to check the SPI bus: MISO, MOSI, SCLK, SSELn, SSELn is the mutiple SPI slave node select pin.

     Check the SPI bus wave will be more easy to find the problem.

    After you check the SPI bus wave, please also share the wave to analysis.

    You can also get the one slave mode SPI bus wave, just used to compare with the multiple situation bus wave


Have a great day,
Kerry

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

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nisargnyk
Contributor I

Hi Kerry,

Thank You for Your reply, And Yes I have connected Different SSEL port pins to different slaves, And observed the same on the Logic analyzer as well, only one SSEL goes low and other stays high while the communication, all the criteria are checked well Sir, but still I'm not getting anything from IC...

Regards..

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kerryzhou
NXP TechSupport
NXP TechSupport

Hi Nisarg,

   Thank you for your updated information.

   Do you use the Logic analyzer test the SPI bus wave? What the data on the SPI bus wave, can the LPC send out the SPI data or not?

    Test the SPI bus wave and check the data, will help you to analysis the detail problems.


Have a great day,
Kerry

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

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