Which of the following is correct statement ?
1
In memory - mapped I/O, the CPU can manipulate I/O data residing in interface registers that are not used to manipulate memory words.
2
The isolated I/O method isolates memory and I/O addresses so that memory address range is not affected by interface address assignment.
3
In asynchronous serial transfer of data the two units share a common clock.
4
In synchronous serial transmission of data the two units have different clocks.
5
None of them