TMS320F28377D: Issue when talking with SRAM, maybe because of D12 connection

Yi zhang

Part Number: TMS320F28377D

Hi,

I have posted before asking question about settings for EMIF related registers to talk with external SRAM. Thanks to Singh's help, I identified D12 had problem. After checking the hardware connection, I spotted that D12(GPIO72) is also connected to external switch for boot mode. I wonder if this is a problem, and how does this affect EMIF since D12 seems always to be "0" and how to solve this? Can anyone give some hints? The previous post may have beem closed because I did get feedback, so I post this new one.

Thanks,

over 8 years ago

0 Vivek Singh over 8 years ago

TI__Guru** 115271 points

Hi Zhang,

Did you probe the D12 pin to see if it ever toggles to '1'? You could configure as GPIO and drive constant '1' via GPIO DAT register and check the pin status?

The register value (3.3K) attach to these pins seems low which could be issue here. You could try replacing it with 10K register and see if that fixes the issue.

Regards,
Vivek Singh

0 Yi zhang over 8 years ago in reply to Vivek Singh

Intellectual 830 points

Hi Singh,

Do you mean configuring D12 pin (GPIO72) as GPIO output and setting value as "1/0"? I did so and it seems D12 pin can be set as 1 or 0. Then I am more confused...

0 Vivek Singh over 8 years ago in reply to Yi zhang

TI__Guru** 115271 points

Thanks for trying this out. Now can you probe this pin on board and send the scope capture for EMIF write and read cycle. Please also have other working datapin in scope capture to compare along with clock.

Regards,
Vivek Singh

0 Yi zhang over 8 years ago in reply to Vivek Singh

Intellectual 830 points

Hi Singh,

The picture below is what I got when increasing two pins 1 each time, yellow for D0 and red for D12. It seems D12 is always "0". I just stopped the scope when starting running, but not sure it is write or read cycle exactly.

0 Yi zhang over 8 years ago in reply to Yi zhang

Intellectual 830 points

Hi,

Finally figure out the problem. There is also a capacitor wrongly soldered to pin D12. We replace it with resistor and everything is working fine! Thanks a lot for your patience and all helpful advice!

Best,
Yi

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TMS320F28377D: Issue when talking with SRAM, maybe because of D12 connection