Shop OBEX P1 Docs P2 Docs Learn Events
Compatability... — Parallax Forums

Compatability...

Sniper KingSniper King Posts: 221
edited 2008-10-03 21:35 in Propeller 1
If I have two identical boards with identical hardware would the propeller software run differently.· Lets say I have a memory overwrite issue, would it manefest itself differently?

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
·- Ouch, thats not suppose to be hot!··


Michael King
Application Engineer
R&D

Check out Project: PSAV Persistent Sailing Autonomous Vehicle

Comments

  • John AbshierJohn Abshier Posts: 1,116
    edited 2008-10-02 17:20
    If they are identical boards with identical hardware and identical software then the software will run identically. If the software runs differently, then something is different.

    John Abshier
  • hippyhippy Posts: 1,981
    edited 2008-10-02 19:00
    Is CNT guaranteed to be the same at turn-on or reset ? I don't think it is so from the very start there can be differences in behaviour. Anything which interacts externally and doesn't get the exact same data at the exact same time can behave differently.

    Same hardware, same software and you should get the same functionality and same behaviour, but one execution may be show up a bug which doesn't show in another execution.

    Also it's rare that anything hardware-wise is truly identical, resistors differ, crystal frequencies differ, voltages differ.
  • TimmooreTimmoore Posts: 1,031
    edited 2008-10-02 20:44
    If you dont intialize local variables but your code depends on them then it can act differently since local variables are not automatically initialized (except for result)
  • Forest GodfreyForest Godfrey Posts: 38
    edited 2008-10-03 20:32
    "The same" is a very relative term. For instance, the clock crystals on your two boards are "the same" but almost certainly run at *slightly* different frequencies. Not enough to cause any major problem, but if you have a race condition that you almost always win, a slight slowdown or speed could cause you to almost always lose. I've actually seen problems at work that manifested themselves on boards (not Propeller boards) at the bottom of a rack but not at the top....
  • Sniper KingSniper King Posts: 221
    edited 2008-10-03 21:35
    Thank you everybody for your responses.· Turns out that the difficulty was my GPS upon powerup would spike power and kill the propeller.· 100uf later and it works perfect!

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    ·- Ouch, thats not suppose to be hot!··


    Michael King
    Application Engineer
    R&D

    Check out Project: PSAV Persistent Sailing Autonomous Vehicle
Sign In or Register to comment.