electronics term: "pulls low" - Tilted Forum Project Discussion Community

longjohns · 11-29-2003, 09:40 PM

what does this mean??

as in:

During a memory read operation, pulls low the INIT# or
RST# pin will reset the devices back to standby mode

thx!

longjohns · 11-29-2003, 09:42 PM

or

It is required to drive INIT# or RST# pins low during system
reset to ensure proper initialization.

goddfather40 · 11-29-2003, 09:53 PM

pulls low = digital logic 0 = pulls it to ground

in context:
It is required to ground the INIT# or RST# pins during system
reset to ensure proper initialization.

longjohns · 11-29-2003, 09:57 PM

ok thanks, that is what i thought, so i jumped a wire between the #rst pin and the ground pin. this is on a chip which is seated in my motherboard. would it be necessary to do this with the power on? with the power supply plugged in? (not truly grounded unless it's plugged in, right?)

kind of a moot point, as it didn't work anyway, but still i'm taking this opportunity to learn a little bit ;-)

goddfather40 · 11-30-2003, 09:48 AM

what I think they want you to do is ground those pins, and then power the system up
or in your other scenario, with the power on, ground the #INIT or #RST pin, and the memory device will return to standby mode

charliex · 11-30-2003, 05:49 PM

be careful digital ground isn't always the same as the chassis ground, and often you'd use a pull down resistor, depending on the design its typically 0-10k ohms ( a 0 ohm resistor is basically a wire in a resistor package )

i'd imagine whatever driving that line is protected so overriding it probably won't hurt it, if its normally high it'll probably have a pull up resistor instead.

you would have to have it switched on, yes.

grounding it with a wire or resistor will cause it to bounce like crazy, ie make and break the connection thousands of times, what effect that will have is difficult to predict

longjohns · 11-30-2003, 07:24 PM

hmm

well i've pretty much decided that this bios chip needs to be replaced, so i wasn't too worried about wrecking it. i read somewhere about someone needing to short the pins on the plcc before they could reprogram it, so i thought i'd give it a try. i looked up the info on the chip from the manufacturer, and made the best guess i could based on that as to which pins to short together...

i have ordered a new chip from badflash, which i hope will set this mobo straight. x-fingers

11-29-2003, 09:40 PM	#1 (permalink)
longjohns Insane	electronics term: "pulls low" what does this mean?? as in: During a memory read operation, pulls low the INIT# or RST# pin will reset the devices back to standby mode thx!

11-29-2003, 09:53 PM	#3 (permalink)
goddfather40 Llama Location: Cali-for-nye-a	pulls low = digital logic 0 = pulls it to ground in context: It is required to ground the INIT# or RST# pins during system reset to ensure proper initialization. __________________ My name is goddfather40 and I approved this message. I got ho's and I got bitches, In C++ I branch with switches -MC Plus+

11-30-2003, 09:48 AM	#5 (permalink)
goddfather40 Llama Location: Cali-for-nye-a	what I think they want you to do is ground those pins, and then power the system up or in your other scenario, with the power on, ground the #INIT or #RST pin, and the memory device will return to standby mode __________________ My name is goddfather40 and I approved this message. I got ho's and I got bitches, In C++ I branch with switches -MC Plus+

11-29-2003, 09:42 PM	#2 (permalink)
longjohns Insane	or It is required to drive INIT# or RST# pins low during system reset to ensure proper initialization.

11-29-2003, 09:57 PM	#4 (permalink)
longjohns Insane	ok thanks, that is what i thought, so i jumped a wire between the #rst pin and the ground pin. this is on a chip which is seated in my motherboard. would it be necessary to do this with the power on? with the power supply plugged in? (not truly grounded unless it's plugged in, right?) kind of a moot point, as it didn't work anyway, but still i'm taking this opportunity to learn a little bit ;-)

11-30-2003, 05:49 PM	#6 (permalink)
charliex Junkie Location: North Hollywood	be careful digital ground isn't always the same as the chassis ground, and often you'd use a pull down resistor, depending on the design its typically 0-10k ohms ( a 0 ohm resistor is basically a wire in a resistor package ) i'd imagine whatever driving that line is protected so overriding it probably won't hurt it, if its normally high it'll probably have a pull up resistor instead. you would have to have it switched on, yes. grounding it with a wire or resistor will cause it to bounce like crazy, ie make and break the connection thousands of times, what effect that will have is difficult to predict

11-30-2003, 07:24 PM	#7 (permalink)
longjohns Insane	hmm well i've pretty much decided that this bios chip needs to be replaced, so i wasn't too worried about wrecking it. i read somewhere about someone needing to short the pins on the plcc before they could reprogram it, so i thought i'd give it a try. i looked up the info on the chip from the manufacturer, and made the best guess i could based on that as to which pins to short together... i have ordered a new chip from badflash, which i hope will set this mobo straight. x-fingers