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How do you determine the RESET line?

Posted: Sat Nov 01, 2003 3:23 pm
by The Robman
I'm going to try and hook up a JP1 connector to the new 4-device Radio Shack Kameleon and to do that I need to figure out which trace goes to the processor's RESET line.

Does anyone know what the best way to determine that is?

Posted: Sun Nov 02, 2003 10:40 am
by The Robman
Anyone?

Posted: Sun Nov 02, 2003 12:42 pm
by johnsfine
You count how many traces go into the epoxy to get a rough estimate of the number of pins on the chip (some no connects or adjacent connects might be hidden).

You guess which chip it might be.

You find some of the obvious traces: Keyboard scan and sense lines, and the control for the IR emmiter, and the IR learning trace (if it has one) and see where those go in. That tells you whether the chip you guessed is possible and how it's oriented. From that you should be able to deduce the reset trace.

While doing that, you should also see where SDA and SCL go in, but they won't help much in deducing RESET, because the pin choices for SDA and SCL aren't as consistent as keyboard pins and IR pins.

Posted: Mon Nov 03, 2003 12:16 am
by mtakahar
I'd start with the oscillator lines. If it's an s3c8f7/f9 in 32-SOP package, the traces from a large ceramic lead to xout (pin 2) and xin (pin 3), and the reset line is the pin 7. (pins are numbered counter clockwise)

Hal