COMPUTER SYSTEM STRUCTURE

1. Synchronous I/O Structure

1.1. CPU do nothing when instruction running

1.2. only allow 1 instruction run at the time

2. Asynchronous I/O Structure

2.1. CPU can do other thing -> can fully utilize

2.2. can return the control to the user while processing

3. STORAGE STRUCTURE

3.1. MAIN MEMORY

3.2. SECONDARY STORAGE

4. CPU PROTECTION

4.1. TIMER

4.2. when timer interrupts, control transfers to the OS

4.3. load-timer is a privileged instruction

5. COMPUTER-SYSTEM OPERATION

5.1. A general-purpose computer system consists of one or more CPUs and a number of device controllers.

5.2. Each device controller is in charge of a specific type of device

5.3. Each device controller has a local buffer

5.4. Interrupt indicates the occurrence of an event from either the hardware or software

5.5. Device controller informs CPU that it has finished its operation by causing an interrupt

6. INTERRUPT HANDLING

6.1. separate segments of code determine

6.2. stop CPU when it is doing and transfer execution to interrupt vector table

6.3. interrupt vector provide address of interrupt service routine for interrupting device

7. STORAGE HIERARCHY

7.1. SPEED

7.2. COST

7.3. VOLATILITY