The case of the missing M7: Where is it in Apple’s iPhone 5s and who makes it? (Solved: NXP)

Along with Apple’s(s aapl) new A7 chip, the iPhone 5s has a low-powered co-processor called the M7. This specific silicon is meant to read the iPhone’s sensors so that applications can use the data without having to rely on the the bigger A7 chip. This offloading of sensor reading is more battery efficient. But where exactly is the M7 and who makes it?

On Friday, iFixit posted its expected full breakdown of the new iPhone components by taking apart the handset. The A7 and all the other chips and bits are available for all to see, save for the M7: iFixit couldn’t find it.

iphone 5c internals

It’s possible that the M7 currently isn’t an Apple chip at all. Instead, it’s could be a signal processing chip made by another company, similar to Motorola’s X8 chip architecture found in the Moto X.

Motorola(s goog) uses a modified Qualcomm(s qcom) chip for the processor and other functions, but includes two separate Digital Signal Processors (DSP) to handle natural language processing and “contextual computing” that handles sensors and the touch display. It’s likely those two chips on the Moto X system on a chip are from Texas Instruments(s txn), according to AnandTech’s Brian Klug.

Here’s another circumstantial clue that Apple doesn’t make the M7 but is instead dubbing someone’s DSP as the M7: The images of the A7 and M7 on Apple’s iPhone 5s product page. Note the markings of the A7 around all the sides? These are Apple’s own chip codes for identification purposes. There are no such markings on the M7 image.

A7 and M7

Granted I could be reading too much into the stock images. And iFixit did find some other Apple-branded chips inside the iPhone 5s, even though none have the M7 branding.

If the iFixit folks can’t find and identify the chip however, I think it likely that the M7 isn’t made by Apple: Just like the Moto X8 it’s both a very useful piece of silicon that’s made by another chip company and smart marketing on Apple’s part.

Update at 11:20pm PT: Not long after I published this post, iFixit released more information on its iPhone 5s teardown. Thanks to Chipworks, the M7 co-processor is indeed not an Apple chip. It’s made by NXP says iFixit and is “an NXP LPC18A1 device that was buried beneath a neoprene-looking cover.”