Reference no: EM133265842

Which of these statements about the way the CPU can access main memory, vs. the CPU accessing eripheral devices, is not true?

1. whether high-level languages or assembly language is being used, the CPU has to call the same kind of operating systems functions (like device drivers) to deal with peripherals

2. most CPU accesses to main memory are for individual words or bytes, while most (but not all!) peripherals are block-oriented or network-oriented devices and transfer lots more bytes back and forth

3. the CPU can directly access the control registers for the main memory bus, and for the I/O or peripheral bus, so the CPU can get data to and from main memory or peripherals in the same amount of time.

4. the CPU can directly read and write in to virtually any location in main memory, in one instruction cycle; but reading and writing to peripheral devices requires lots of device-specific subroutines, and these take a lot more time to execute.

Provide explanation...