Very good find, I was thinking it might be from the Ingenic family as their processors have wide range of peripherals right from the chip and it's used in many embedded products out of China so you just confirmed that for sure with your find. It's a nice processor for embedded products CPU & VPU run 360mhz-400mhz.
But It might not be the Jz4755 but a 4750 or 4740 as the 4755 would be over kill for a USB device with USB power specifications max limit 500mA and that is for Hi-Power USB device and while you first connect to USB that limit is only 100mA and this CPU would be in the Hi-Power range for sure.
I heard that for USA customers this thing is only $17.99 and for other countries it's up to $29 so price is right for sure.
Originally Posted by moretex
I just reviewed all the data sheets for the CPU and I can now confirm Moretex you guessed 100% that is a Jz4755 as it's the only one that has the LQFP176 package.