Can't change segment pointer on SN65DSI86 using indirect method

Victor Praxedes

Hi,

I'm having some trouble changing the segment pointer to read a Display ID extension block located at the 0x100 address. I've followed the datasheet by the letter, it evens ACK my write command on address 0x30, but when i do an indirect read after this, what i get is the same edid that i get when i read without changing the segment pointer.

I have tried inserting the indirect write code before step 16 of the datasheet indirect read tutorial but it behaved the same.

Can anyone help me?

over 8 years ago

0 Joel Jimenez0 over 8 years ago

TI__Mastermind 18655 points

We are reviewing this and we'll have some feedback later today. Please, share the display datasheet.

0 Victor Praxedes over 8 years ago in reply to Joel Jimenez0

Prodigy 70 points

Hi Joel,

I don't have access to the monitor datasheet, all i got are the technical specs and a datasheet in german, which are the same technical specs.

I"ve managed to read the Display ID today once, and only once. After messing with the indirect read address, i was trying to read from 0x52, and getting several NACKs, i changed back to 0x50 and did the same thing i was doing before: Change Segment Pointer > Indirect EDID Read and bam, i got the display ID block. Then i tried to read again and it read the main EDID block :(

I can post some code if you want.

Hope those "datasheets" are enough.

0 Joel Jimenez0 over 8 years ago in reply to Victor Praxedes

TI__Mastermind 18655 points

Hello Victor,
We will need to see an AUX analyzer capture of the transaction to understand what would be failing.
Regards

0 Victor Praxedes over 8 years ago in reply to Joel Jimenez0

Prodigy 70 points

Unfortunately, I don't have an AUX analyzer, but i have a really sweet scope. Will that suffice?

0 Victor Praxedes over 8 years ago in reply to Joel Jimenez0

Prodigy 70 points

I have one more question Joel. I was wondering if there was some way to get the current segment pointer, so i could know for sure it was changed. Is there any command that would return the current segment pointer?

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Can't change segment pointer on SN65DSI86 using indirect method