TMS320F28375S: TMS320F28375S: IO OUTPUT

Lei wang

HI Sir:

We find that The TMS320F28375S PIN 151 IO-PIN When i set it out Low. But sometimes it can be changed by External factors. it means i set low ,but sometimes the PIN out is high.

over 8 years ago

0 Nima Eskandari over 8 years ago

TI__Guru 52220 points

Just to clarify, you select the pin as GPIO and set it low, but due to other things in the system the pin goes high?

0 Lei wang over 8 years ago in reply to Nima Eskandari

Expert 1620 points

Yes。It set Low， and Maybe Pull high by external signal，but when the signal has been removed.It should be return to low.But it not.

0 Nima Eskandari over 8 years ago in reply to Lei wang

TI__Guru 52220 points

I'm testing this on my lab setup and will get back to you with an answer.

0 Lei wang over 8 years ago in reply to Nima Eskandari

Expert 1620 points

we test that when the pin be used as pwm -out It is OK. But as GPIO it not OK, you can pull high by VCC and no limit Res.Then Remove VCC. This is more likely to happen. of course, when we find it Pull high by external signal,I have the Res.

0 Nima Eskandari over 8 years ago in reply to Lei wang

TI__Guru 52220 points

There is max clamping current for all pins (20 mA) if this is exceeded the device may be damaged. When you say the internal register jumped to 1, which internal register are you talking about? Also does this mean that when you remove the source from the pin it doesnt go back to the original value?

0 Lei wang over 8 years ago in reply to Nima Eskandari

Expert 1620 points

Yes

0 Nima Eskandari over 8 years ago in reply to Lei wang

TI__Guru 52220 points

I believe this damages the device. You will need to use an external buffer capable of handling this. Shorting the opposite polarity voltage to our IO (Set as output) with a powerful enough source to pass the 20 mA limit will damage the device.

0 Lei wang over 8 years ago in reply to Nima Eskandari

Expert 1620 points

the device have this issue.When We use it in normal.The VCC source by the Res to The GPIO. When We find that we test without the res. I can understand the device is damaged under this test method. But the issue has not been solved.

0 Nima Eskandari over 8 years ago in reply to Lei wang

TI__Guru 52220 points

Can you clarify again what the problem is?

0 Lei wang over 8 years ago in reply to Nima Eskandari

Expert 1620 points

The Pin use as PWM it is normal, But when I use as GPIO. Sometimes. I set Low，Then pull high .When i remove the VCC, it also is high. but it should return to low.