Controlling TP1 on MOD54415 from an external circuit

[Watzlavick]

I'm going to be using a MOD54415 in an application where it may be very inconvenient to get to the TP1 header if I need to restore the default config record for some reason. So, I want to use an external circuit - a relay would work of course but I assume this is just a pin into the CPU. It appears that one of the pins (the round pad) connects to GND and the other one (square pad) is pulled up to VCC through a ~3.5k resistor. If so, I can just use a 74HCxx to pull the square pad down if I need to recover the module. Is this a correct assumption of the TP1 wiring? The particular H/W version is 1.5 but I plan to get some newer modules and I'd like it to work on those too.

Thanks,
-Bob

[pbreed]

Yes pull it down to logic zero... the other pad is just ground...

[Watzlavick]

Thanks! Is it possible to get the dimensions of TP1 relative to J1 or some other reference point on the board? I plan to install a 2-pin header on the module that will mate with a female header on my baseboard, similar to J1 and J2. I could guess and get within 0.02 or so but it would be better to get the real dimension (hopefully it is the same between revisions of the board). Unfortunately once I install a 2-pin header onto the module, I won't be able to use the MOD-DEV-70 anymore because one of the pins will interfere with the top of the SD card slot. I suppose I could use a right-angle header instead on the module and then use a short 2-pin cable to connect to my baseboard.

-Bob

[mbrown]

I have the square hole as practically in line with the J1 header (further away from the nearest board edge by 5.5 mils (0.14mm)) and down 338 mils or 8.58 mm away from pin 50.

These numbers come straight from the design.

[Watzlavick]

I guessed 0.330 inches so I got pretty close. Thanks again!

-Bob