SuperCIC for PIC10F322

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poorstudenthobbyist
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Re: SuperCIC for PIC10F322

Post by poorstudenthobbyist »

I believe LS series parts output 3.3V instead of 5V. Which certainly could have an effect on how much noise is radiated into the neighboring circuits. I'm slightly annoyed that I have to worry about conducted/radiated emissions - I thought I only had to deal with that kind of stuff at work, certainly not for SNES carts!
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Memblers
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Re: SuperCIC for PIC10F322

Post by Memblers »

I mentioned this problem to kevtris, and he had some suggestions:

- check PIC config bits, and make sure power-up delay is turned off. Could be that the SNES and SNES Jr. have different reset lengths, and the PIC wasn't out of reset yet.

- use provided hex file rather than build from source. Microchip made changes to their assembler that affects the bankswitching macros, and if true, that could completely break the code timing.
poorstudenthobbyist
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Re: SuperCIC for PIC10F322

Post by poorstudenthobbyist »

Thanks for the tips!

I used the same 10F322 on two of my boards - one that uses the 27C322, one that doesn't. I didn't reprogram the 10F322 between swapping boards, and the non-27C322 board worked fine. I've been using the HEX file to program as well, not the .asm file - if the timing was broken by the assembler, wouldn't I have the problem on both boards?
lidnariq
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Re: SuperCIC for PIC10F322

Post by lidnariq »

(Un)fortunately, 10F322 doesn't have any bankswitching, and I'd disabled the power-up timer in the in-band fuses.
poorstudenthobbyist
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Re: SuperCIC for PIC10F322

Post by poorstudenthobbyist »

Well, I have no idea what the problem is with this. I made two more board designs - both with 10F322s, both with very thick traces and power/ground planes overlapping the traces. No interference from any other line, except the trace coming from the reset pin on the cart connector has to overlap a few traces, but that's not switching at all so it shouldn't be a problem.

One design works, one doesn't. The one that doesn't is doing the same thing as what I described earlier. Even tried swapping the 10F322s between the working and non working board to see if it was a bad chip, but the problem follows the board. Both boards work with 12F629. So I don't know what the problem is. I guess I'll be abandoning my efforts to get the 10F322s working and stick with the 12F629, annoyingly.
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Kayumba
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Re: SuperCIC for PIC10F322

Post by Kayumba »

How program 10F322 with TL866 ?
When i type 10F322 in search Device,
Minipro dont find that part.

Any idea ?
poorstudenthobbyist
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Re: SuperCIC for PIC10F322

Post by poorstudenthobbyist »

Markfrizb wrote: Tue Aug 25, 2020 10:18 pm I think the LS series chips help with noise, it’s been a looong time since I researched those so I could be wrong, but I think the SCHOTTKY process helps with noise.
Since the LS series of parts output only 3V on their outputs, can the SNES reliably read the data correctly? I know it functionally works (I am doing it right now) but can the SNES reliably operate on CMOS level logic?
(I have to assume this is addressed somewhere else on the forum but I am not good at searching for it, apparently haha)
lidnariq
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Re: SuperCIC for PIC10F322

Post by lidnariq »

TTL logic pulls high enough when unloaded, but not when under load. Since nothing else in the SNES is TTL logic other than what's on the cart, it often works.

(Output pull-up stage for 74LS parts is a 120Ω resistor and a saturated NPN BJT. Unfortunately, I cannot find a PDF of an official 74LS family specifications as I can with 74HC parts)
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