Although at least part of the sales volume difference can be explained by NXP having had more expensive i.MX range available (and others), so in terms of chips sold they might be closer to each other.
> This combined A7+M4 device is unusual
I'm not sure if I'd say that, previously NXP did the exact same thing with i.MX7, and TI with their AM5x. And of course don't forget the classic AM3x which had PRUs filling part of the same role.
This report from 2016 puts NXP at twice the marketshare over STmicro who are sitting steadily in the fifth place:
https://epsnews.com/2017/05/01/nxp-tops-microcontroller-supp...
Although at least part of the sales volume difference can be explained by NXP having had more expensive i.MX range available (and others), so in terms of chips sold they might be closer to each other.
> This combined A7+M4 device is unusual
I'm not sure if I'd say that, previously NXP did the exact same thing with i.MX7, and TI with their AM5x. And of course don't forget the classic AM3x which had PRUs filling part of the same role.