It can be either.
synchronous
Because they contain clock recovery circuits
If a process requests that the O/S write data to disk, and has to wait for it to be written before continuing, then that is Synchronous. If the process does not have to wait for the write to be completed, that is Asynchronous. Synchronous is real-time.
Different data rate speed (for rs232 is lower), usb is more flexible and takes less energy. Different instructions and commands. If you are a programmer then it's easier for to work with usb then with rs232.
Synchronous circuits operate under the influence of s clock pulse while asynchronous circuits operate without the influence of a clock pulse
In asynchronous transmission , the receiver and the transmitter each use their own clock signals so its not possible to know when a word starts and stops. while in synchronous , the receiver and the transmission have common clock signals.
yes
it is the difference between the synchronous and asynchronous speed of a induction motor
Synchronous flip-flops change outputs synchronously to a clock signal, while asynchronous flip-flops can change outputs regardless of the clock signal. Asynchronous flip-flops are not as commonly used due to potential timing hazards, while synchronous flip-flops are widely used in digital circuits to ensure reliable operation.
1. Syncrhonous bus includes clock in control lines whereas asynchronous bus is not clocked. 2. the devices which need to be connected by synchronous bus should be at same speed whereas an asynchronous bus may connect many devices with varying speeds. 3. A fixed protocol is defined to communicate using synchronous bus which is relative to the clock. An asynchronous bus uses handshaking protocol.
i/o data transfer speed of time
Asynchronous vs. Synchronous Communication