Without having read the data sheet… It is probably to keep the devices synchronized. Reading data from an unsynchronized input takes, um, waving hands here, 2 t

Without having read the data sheet… It is probably to keep the devices synchronized. Reading data from an unsynchronized input takes, um, waving hands here, 2 to 10 times the effort and resources. If you are old enough to remember serial ports on computers, this is the “16 times oversampling!” bullet point. They oversampled and then state machined their way back to figuring out where the sending machine’s clock was thinking the bit changes were. Bonus fun depressing asynchrony fact: Whenever your chip samples an asynchronous input there is a chance of the logic getting the change just at the wrong time and entering a meta stable state which is neither high nor low for an arbitrarily long time! The best you can do is minimize the probability and probable duration. So, happy new year, all your computers are just rolling dice billions of times per second.