NH Dash - XC68HC711 UPA-S Programming problems

[pabloniusz]

Hello,

I have issues with flashing EEPROM on the New Holland TM135 Dash.
It uses XC68HC711 , KG2CPU4 , mask 0H85A mico - looks the same as in this thread
(https://www.digital-kaos.co.uk/forums/showthread.php/660997-Pinout-help-new-holand-xc68hc711?highlight=xc68hc711)
I am able to
* connect to the micro - so my connections are most likely OK.
* read out the EEPROM content
* write to it
* but when i try to verify i'm getting a lot of errors.

Because this dash belongs to me - it is a training board (and I already backed up the content of the memory) I attempted to program some patterns to see where i'm failing:

658454

What i got after programming and reading memory out again is this :

658455

So it only programs every second row and only half of it ...
Just to note that after re flashing original content, dash is able to start up but it displys error indicating that constants in EEPROM are not correct.
This is where I need your help :)

Can anyone have any idea what i'm doing wrong? Any ideas welcome :)

[Moe1988]

most probably wrong conx .. try reading multiple times and see if you get stable results , or verify multiple times