There can't be separate touch controller for "multitouch". In fact the word multitouch is not even a technical term. Touchscreens are multitouch by default. The two chips probably work in parallel to handle the needs of the larger touchscreen.
Galaxy Tab 10.1 actually has three Atmel touch controllers, which is probably why scrolling on it is smoother than most Android devices.
Enlighten me: How exactly does having two, or even three controllers make for smoother scrolling? Assume I know nothing about touch screen controllers!
Speculation (I know nothing about the technology, either):
There are two factors to smooth scrolling:
- high-resolution, low latency measurement of finger location.
- fast, low latency scrolling of screen content.
I guess one can use multiple detectors to increase spatial resolution of position detection. For example, with two detectors that each have a X DPI resolution, one could place them in two layers, staggered from each other behind the screen to double resolution in one direction.
Alternatively, if there is no technical limitation to DPI, it might be a limitation to the controllers one can buy. If they have a maximum number of lines they can detect, one could use two controllers, each one covering half the screen, and double resolution that way.
