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zlsa | 2 years ago

If a USB-C to USB-C cable only had wires for VCC and GND, here's what wouldn't work:

* Data (this one is fairly obvious) * Power (since the CC wire in the cable is missing, and a compliant USB-C power source will refuse to output power unless the CC wire is terminated on the other end which signals what type of device it is)

You'd need at _least_ the CC wire as well.

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hedora|2 years ago

Can’t the cable terminate it instead? That would save a lot of wire, and consumer expectations for USB-C reliability are just above “might catch fire” and below “I’d be surprised if the cable was incompatible or failed so quickly”.

duskwuff|2 years ago

You'd end up with a cable that only worked for "slow charging" (5V / 500 mA), and even then only in one direction (because the cable could only pretend to be Rp+Ra or Ra+Rd for one side). It's easier to do the right thing.