LP-AM243: Can not get SPI to work on LP-AM243 Launch Pad eval board

Rajeev Bharol

Part Number: LP-AM243

Hi,
In order to find if SPI works, I loaded the inbuilt example mcspi_performance_8bit_arm243x-lp_r5fss0-0_nortos_ti-arm-clang

and expected it to work. It did print a message saying "All tests have passed" but when I probe the SPI0 Data line, I do not see any activity on it. I do see clock being generated on the clock pin though but no activity on data lines and Chip select is also always in low state. I am probing the corresponding pins on Booster header. I later tried to use the api function MCSPI_Transfer but that fails right away with error code 3 (meaning transmission failed). What am I missing?

Thanks.

over 3 years ago

0 Ming Wei over 3 years ago

TI__Guru 57715 points

Hi Rajeev,

I tried the same example from MCU+ SDK 08.04.00.17 on AM243x LP. The SPI0_CLK is not on. When I tried the same example in MCU+ SDK 08.03.00.18, the SPI0_CLK is toggles 5 times as the following screen capture:

So apparently there are some issues with the SPI examples in the MCU+ SDK 08.04.00.17. I will certainly report that issue to the software development team. Meanwhile, can you use the SPI examples from MCU+ SDK 08.03.00.18 instead.

Best regards,

Ming

0 Rajeev Bharol over 3 years ago in reply to Ming Wei

Prodigy 90 points

Thanks Ming. I will try version 18 and update here.

0 Rajeev Bharol over 3 years ago in reply to Ming Wei

Prodigy 90 points

Hi Ming,
I just installed 08.03.00.18 library. It does NOT have MCSPI examples.. I am using Windows Machine.

0 Rajeev Bharol over 3 years ago in reply to Ming Wei

Prodigy 90 points

Hi Ming,
Also, I am able to see the clock and chip select. It is the data out that I do not see.

0 Ming Wei over 3 years ago in reply to Rajeev Bharol

TI__Guru 57715 points

Hi Rajeev,

Did you download and install the MCU+ SDK for AM243x 08.03.00.18 from: MCU-PLUS-SDK-AM243X Software development kit (SDK) | TI.com?

The example is at C:\ti\mcu_plus_sdk_am243x_08_03_00_18\examples\drivers\mcspi\mcspi_performance_8bit\am243x-lp

Best regards,

Ming

0 Ming Wei over 3 years ago in reply to Ming Wei

TI__Guru 57715 points

Hi Rajeev,

Here is the screen capture of all 4 pins of SPI0, when the example from 08.03.00.18:

I used SPI0_CLK as trigger and 3.3V.

Best regards,

Ming

0 Ming Wei over 3 years ago

TI__Guru 57715 points

Hi Rajeev,

I downloaded and installed the AM243x MCU+ SDK 08.03.00.18 from the ti.com, but I will check it again.

I just tried the same example from 08.04.00.17. Here is the screen capture of all 4 pins of SPI0:

Can you try it again with SPI0_CLK as capturing trigger (up edge) and 3.3V?

Best regards,

Ming

0 Ming Wei over 3 years ago in reply to Ming Wei

TI__Guru 57715 points

Hi Rajeev,

I just downloaded and installed (at C:\temp\ti) the MCU+ SDK for AM243x 08.03.00.18 from the link I posted before:

MCU-PLUS-SDK-AM243X Software development kit (SDK) | TI.com.

The example is at:

C:\temp\ti\mcu_plus_sdk_am243x_08_03_00_18\examples\drivers\mcspi\mcspi_performance_8bit\am243x-lp\r5fss0-0_nortos

Best regards,

Ming

0 Rajeev Bharol over 3 years ago in reply to Ming Wei

Prodigy 90 points

Which version of Code Composer studio are you using?

I was able to download the AM243x 08.03.00.18 version and I can see the example but what I see is that in example.cfg, D0 is used as Input and Tx is enabled on it. Is that right?

0 Ming Wei over 3 years ago in reply to Rajeev Bharol

TI__Guru 57715 points

CCS 11.2.0

Since it is TX only, so the "Input Select" uses "D0" is OK.

Best regards,

Ming

0 Rajeev Bharol over 3 years ago in reply to Ming Wei

Prodigy 90 points

Thanks.

0 Rajeev Bharol over 3 years ago in reply to Ming Wei

Prodigy 90 points

One thing I still do not understand is why is D0 selected as input in this Transmit only example. Data is being transmitted on D0 but in the generated code,

.inputSelect = MCSPI_IS_D0

in example.syscfg also, input select is D0. Why? D0 is out put.

+1 Ming Wei over 3 years ago in reply to Rajeev Bharol

TI__Guru 57715 points

Hi Rajeev,

You can change the Input to D1. The example should work the same.

The D0 as Input is a left over of the loopback example, because the D0 was set to TX and RX for loopback mode.

Best regards,

Ming

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LP-AM243: Can not get SPI to work on LP-AM243 Launch Pad eval board