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DS1338 and DS323x Realtime Clock modules compatible?

TTL

Oct 24, 2013
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I have a vintage computer where I can add a battery-backed DS1338-based RTC (Realtime clock) module for it to keep the time by attaching the SCL and SDA outputs, but have heard that they're not very accurate (although better than the DS1307 which it's apparently compatible with).

The DS3231, DS3232 or DS3234 are far better I've been told and there are several ready made modules based on these available. But are they compatible with the DS1338?
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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What do the datasheets say?
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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There's various Maxim application notes which compare these chips.

One important factor is that the 1338 is a low power design, while the 3232, with it's TCXO is high power (to run the heater).

The pinouts are probably totally different, but I'm sure you don't mean compatible in that sense. You'd have to look at the I2C stuff in more detail, but I suspect that the 3232 is probably a superset.

I note that the 3232 has a reset triggered by one of the I2C lines remaining in one state for more than a certain period. This is specifically noted as limiting the minimum frequency it can be operated at. I have no idea what frequency your vintage computer uses.
 

TTL

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No, I meant compatible as in "are the 1338 and 232x modules interchangeable", not the actual IC.
The datasheets are a bit over my head, but it seemed the transfer protocol (or whatever it's called) is the same, which is what's important here (that the computer receives the same type of data regardless if the hardware is a 1338 or 232x.

I don't know the details about how this is received on the vintage computer -I just had some information on how to attach a 1338-based RTC module to it and thought I'd improve on that.
 

TTL

Oct 24, 2013
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PS. By "modules" I meant of course the entire ready-to-use realtime clock circuit boards that you buy on eBay or wherever.
sku_435088_1.jpg
 
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