HETLBPDIR IODFTENA Field purpose for TMS570LS0432 device

Hi Pashan,

No, Digital/Analog loopback is selected by the HETLBPSEL register.

IODFT is a factory test function.  Not sure why it got into doc or header files.  Where did you find this?

-Anthony

Hello Anthony,

In spnu517.pdf [TRM for TMS570LS043 Corona Device] I found it as shown below.
Please help me understand what value to set this field for my normal HET use.

Thank you.
Regards
Pashan

Ah, got it.  I think there was another thread on this wasn't there,  whether the value should be 0x5 or 0xA for enable.

It should be disabled for NHET operation.  Iet me check on the value though.   I'd be very surprised if it defaults to enabled.

-Anthony

Follow-UP:

Yes 0xA is Enabled.  0x5 is Disabled.  So you should just write back 0x5 in this field always for functional operation.
This is my chapter to maintain, so I'll make the update now although it'll take a while to ripple through to the published doc.
Sorry about this.

Hello Anthony,

I am confused about the NHET Function now.

Whether I write 0x05 or 0x0A within IODFTENA Field, I always see at the HET Pin correct output.

I thought for functional NHET use according to your modified information, I should always use 0x05.

And if I write 0x0A instead, then I expect to see some anomalous behaviour at NHET Pin level.

Is that correct? If yes, then can you please explain what anomalous behaviour I am expecting to see?

Thank you.
Regards
Pashan

Pashan,

I looked at the RTL code; and think I understand now what's going on.   We have something called IODFT that's for factory test where there's pattern generators and LFSR's used to test IOs but that doesn't appear to be what this field does,  even though it's named IODFTENA.

From what I can tell, this field should really be called 'Loopback Enable' as it appears to gate whether the loopback function is turned on or not.   So I believe it should be changed to LBENA:   0xA enable looback.  0x05 disable loopback.

I'm going to forward this to a colleague should be able to confirm this as he used to manage the IP design.

-Anthony