Grounding Data lines on a ROM

[Maviryk]

Hey,
Need some ROM flash guru's help.

The theory is that by grounding a certain data line on a ROM it would crash a certain hardware ROM flash block.

Now the software side of the theory is tested and sound.

The question is... is grounding the data line on a ROM a "safe" idea? As in does anyone know if it is likely to burn the rom chip or cause irreparable damage.

Thanks.

[four4875]

i thought roms usually have a certina pin that has to be either raised or lowered (depending on the chip) to enable flashing..

so why not use the built in mechanisms? i would think grounding the data line would prevent any data from being read or written to it, if it is a pin that is bidirectional. if its an input only, and there is enough of a resistor between the pin and its data source to sink any current it may have to, grounding it should work to prevent any data from flowing. but i wouldnt really want to risk it, you could be giving a dead short to some other component, causing undesirable results.

[klingens]

You can only "burn" a chip by applying too much voltage or current. So ground is by definition very safe for that chip. However pulling a pin in a circuit to ground can cause a short in another part of the PCB and can burn _that item_ over there. So pull the pin to ground with a resistor. The resistance you'd need depends on the circuit tho. no hard number available. Generally it's a low number however.

ANd it won't "crash" anything. it just pulls a line to zero which means a constant false or whatever.

[Maviryk]

four4875, the ROM in question has the "built-in" flashing mechanism locked out.

klingens, maybe I used the wrong term when I said "crash", more like screwing up the command execution of the code. Well, crashing the code, not the hardware(I explained it wrong the first time).

Anyhow, I think I've found out what I need to know. THanks for your help.