TMS570LS3137: Mibspi Usage for TMS570

Hi Jagadish,

Firstly thanks for response. After solved this issue we encountered some issues about buffer management. Like we set a transmit buffer with buffer size as 4. After we transmitted this buffer, received buffer filled by only first transmit buffer index response. How we can access ram buffers properly.

Best Regards,
Furkan

Hi Furkan,

Furkan Gungor said:

After we transmitted this buffer, received buffer filled by only first transmit buffer index response.

You mean that, if you are sending 4 characters you just receiving one character?

Can you please share your code?

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Thanks & regards,
Jagadish.

Hi again,

No, if i give an example about this topic will be like: when i sent {0x0030,0x0031,0x0032,0x0033} these message responses will be like {0x0002,0x00020x00020x0002}. How does this process works also is this module transmitting sequentially or parallel ?

Thanks,
Best Regards,

Furkan Gungor said:

No, if i give an example about this topic will be like: when i sent {0x0030,0x0031,0x0032,0x0033} these message responses will be like {0x0002,0x00020x00020x0002}. How does this process works also is this module transmitting sequentially or parallel ?

Are you testing loopback? are you expecting same data what you sent?

No i tested with an accelerometer. But i tested with loopback mode before and it was okey. I expected different values for each transmit index but i couldnt get it.

My doubt here is, 

How are you confirming TMS570LC3137 not receiving data properly? what if the accelerometer is sending wrong data?

Did you have any logic analyzer to test the data out from the accelerometer? or did you test it with any other SPI master device?

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Thanks & regards,
Jagadish.

I assumed tms570 transmission work as sequentially, accelerometer couldnt catch these sequential so this sensor only gave me first index response. 

Accelerometer doesnt send any wrong data depends on first index. If i send byte by byte i get true response from sensor. 

Hi Furkan,

The SPI Parallel/Modulo Mode Control Register (SPIPMCTRL) register will control the data to be shift parallel or sequentially.

If the PMODE0 value in this register is zero, then the data will shift sequentially on single line only.

If you provide your code, then i can verify how the data is shifting out of the controller.

I would also suggest you refer below thread as well, in recent time we saw one data corruption issue in MibSPI which is resolved by providing some delay between chip select active to transmission:

(+) TMS570LS3137: MibSPI Slave -> Master transfer 1st value missing first bit - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

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Thanks & regards,
Jagadish.

HI Furkan,

Furkan Gungor said:

After I struggled a lot of time on this data handling i realized my mibspi buffer only transmit once. I couldnt update transmit buffer or receive buffer after one time communication.

Good to hear that you solved the issue.

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Thanks & regards,
Jagadish.

I wish I can but not today i guess :D. The issue still continue.  

Here my code part. The aim here is send data with different values and receive their responses but i couldnt become successfull. I got only first message response. 

For example: 

Expected Transmission dataset  and corresponded values will be like:

Tx             Rx

0x00        0xE5

0x30        0x02

0x20        0x2C

at the run time I got only E5 0x02 and 0x2C never occurs.

Hi Furkan,

What is the Transfer Group Length you configured in your example?

As you are trying to send byte by byte you should configure the length as 1 only.

And if possible, please provide complete project to verify all the configurations.

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Thanks & regards,
Jagadish.

Hi again,

The transfer group configuration is same with yours. I cant share my project because of some restrictions, i am sorry about that.

I reviewed my code to find where issue comes from. I checked some related register values and seemed no problem. If you want to know specific register values i can share with you if you want.

Best Regards,

Furkan

I create an example project with same register values as my project . 

adxl345_mibspi_tms570.zip

Hi Furkan,

I don't have TMS570LS3137 board, so i just recreated your project on TMS570LC4357. I made settings same as yours and i also copy pasted your code and did the testing.

Here is the result i got from the mibSPI3

This is the output after first iteration, it is sending as you would like to send i.e. 0x00, 0x30 and 0x00.

So may be this is as per your requirement only.

The only things i don't understand in your code is

1. You are declaring "t" as unsigned char but you are moving the values like 1000 and 100000 into this variable, this will just truncate the value moved into the t.

2. First time you are sending one 0x00 and after that you are just looping 0x30 and 0x00 in the while(1), this is exactly what you want or you just overlook anything here?

I am attaching my tested code for your reference:
MIBSPI3_TEST_LC4357.zip

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Thanks & regards,
Jagadish.

Hi jagadish,

Firstly thank you so much your interest and effort. After that my answers are:

1. Actually t variable not so important. I only use this variable create delays between variables. In other project i created this variable as unsigned integer 32 bit. 

2. My desire same as your saying. I want to access some registers and get their values sequentially on the accelerometer.

Best Regards,

Furkan

Hi Furkan,

Furkan Gungor said:

1. Actually t variable not so important. I only use this variable create delays between variables. In other project i created this variable as unsigned integer 32 bit. 

2. My desire same as your saying. I want to access some registers and get their values sequentially on the accelerometer.

Understood this.

But as I shown in the logic analyzer waveforms, I didn't see any issues with your code, and it is working as we expected.

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Thanks & regards,
Jagadish.

Hi Jagadish,

So you mean this issue about sensor bandwith or etc. right ?

Also for example if i use buffer length as 10 or much than this. will ı expect this buffer send data sequentially right ?

Best regards,

Furkan

Hi jagadish,

Thanks a lot for explanation and help for these issues :D. I got it where the issues come from.

Have a good day,

Furkan

Best Regards,