Apple Watch 2:1 Display Multiplexer

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Level 1

8 points

Apple Watch 2:1 Display Multiplexer

Hello All,

I notice the apple watch S1 has a display port multiplxer - A 2:1 mux from NXP. What is it used for and how? what problem is it trying to solve?

Thanks

Chandra

iMac, Mac OS X (10.6.8), Facetime

Posted on Jul 29, 2015 12:05 PM

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Answer 1

John Galt

Level 10

155,906 points

Jul 29, 2015 12:30 PM in response to chandrag

A "multiplexer" is a term that can apply to a very broad range of devices whose purpose is to aggregate a number of input signals into a combined output. Its specific purpose in the Watch is not a subject Apple is likely to discuss.

NXP is one of many Apple parts suppliers. As far as I know their component is only used for its NFC function.

what problem is it trying to solve?

I'd ask you the same question 🙂

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Answer 2

chandrag Author

Level 1

8 points

Jul 29, 2015 12:36 PM in response to John Galt

Thanks John.

NXP already has the NFC controller and the signal booster chips in there so I don'y think this "interface" chip is used for anything NFC related ... I can think of possible ways that the mux could be used for ... Possibly use the STMicro MCU (with external TCXO) to track and update teh watch display when teh user is not initiating any actions and the rest of the S1 can be in sleep/off ... just thinking aloud ...

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Answer 3

John Galt

Level 10

155,906 points

Jul 29, 2015 12:41 PM in response to chandrag

That's as good an idea as any. The Watch has to implement some very creative power-saving features given its small battery, and the display is almost certainly its biggest load.

All we can do is speculate though.

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Answer 4

chandrag Author

Level 1

8 points

Jul 29, 2015 1:22 PM in response to John Galt

Thanks John.

If you don't mind me asking, are you an Apple Employee yourself?

Best Regards

Chandra

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