SPI Chip Select does not pull down

Raghavendra Shenoy

Hi,

I am trying to get the SPI working on one of my setups.

The SPI master is C2000- F28027 device. And I am using one of the booster packs as SPI slave.

I am using the sample example 'spi_loopback' as the reference. When I try to execute this with my booster pack, I see that the chip select (J2.3) does not pull low. Because of this C2000 device is not able to communicate with the slave.

I tried to execute this example stand-alone, i.e, without any booster packs connected to it. I can still see the same behavior.

Please give some inputs.

Thanks & Regards,

Raghavendra

over 12 years ago

0 Gautam Iyer over 12 years ago

Guru 192875 points

Hi Raghav,

Did you try out the sample examples of loopback with interrupts? Do they work or same issue?

Regards,

Gautam

0 Raghavendra Shenoy over 12 years ago in reply to Gautam Iyer

TI__Mastermind 27095 points

Hi Gautham,

I am seeing the same issue with loopback interrupts as well.

The Chip Select neither remains high nor low. Its at an intermediate state! Is J2.3 the right pin to probe for Chip select on the board (for GPIO 19) ?

Am I missing something here?

Thanks & Regards,

Raghavendra

0 Gautam Iyer over 12 years ago in reply to Raghavendra Shenoy

Guru 192875 points

Hi Raghav,

Its at an intermediate state!

What intermediate state? Half of logic high? Did you measure the voltage?

Is J2.3 the right pin to probe for Chip select on the board (for GPIO 19) ?

J2.2 is the chip select pin.

Regards,

Gautam

0 Raghavendra Shenoy over 12 years ago in reply to Gautam Iyer

TI__Mastermind 27095 points

Hi Gautam,

After checking further I could figure out that the Chip select pin is at J2.2 on the C2000 launchpad (LAUNCHXL-F28027).

But as per the standards, the chip select pin is placed at the 3rd pin of the outermost header. Are there plans to change this on the C2000 launchpad?

Thanks & Regards,

Raghavendra

0 Gautam Iyer over 12 years ago in reply to Raghavendra Shenoy

Guru 192875 points

Hi,

But as per the standards, the chip select pin is placed at the 3rd pin of the outermost header. Are there plans to change this on the C2000 launchpad?

I don't think C2000 launchpad would undergo any further changes.

Regards,

Gautam

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SPI Chip Select does not pull down