EMI-Mode for output pins

Markus Uhle

Hi,

on our RM46L852ZWT I want to enable the output buffer low emi mode for all (but at least for the EMIF) output pins.

The register description (technical manual page 164) is not really clear to me. It seems that the low emi mode is enabled by clearing the corresponding bits.

I did it (I set bit 15..0 in the GPREG1 to 0x0000).

A direct comparison with a spectrum analyzer and a RF-current probe showed no difference.

Do I have to do something else to enable the EMI-mode?

Regards,

Markus

over 11 years ago

0 Enrique Lizarraga over 11 years ago

TI__Expert 4580 points

Good morning:

I'll forward your post to one of our experts to provide the required feedback.

Regards.

0 Zhaohong Zhang over 11 years ago in reply to Enrique Lizarraga

TI__Mastermind 22715 points

Markus,

You can set the I/O pins in low EMI mode via General Purpose Register (GPREG1). See details at page 162 of TRM.

Thanks and regards,

Zhaohong

0 Haixiao Weng over 11 years ago

TI__Genius 13810 points

What you did is correct.

What you have seen in the spectrum analyzer via a RF-current probe might also be true.

The low EMI buffer can reduce the noise ONLY if this noise is coupled from the IO pins or from the core through the silicon.

If the noise is generated by the IO toggling itself, Low EMI buffer in this device will not reduce the noise level.

Regards,

Haixiao

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EMI-Mode for output pins