Chapter 24 Flashcards
What in interrupt
It is a signal send to processor to start or stop working
What is Programmable Interrupt Controller (PIC)
Since there are many devices generating interrupts and there is only one pin going inside the processor and one pin cannot be technically derived by more than one source. A controller is used in between called the Programmable Interrupt Controller (PIC). It has eight input signals and one output signal.
How processor know from which source interrupt generated to it
From mapping mechanism
What is IRQ
The eight input signals to the PIC are called Interrupt Requests (IRQ)
How much IRQ are there in a processor
8
What is highest priority IRQ
0
What are IO ports
Processor communicates with peripheral devices like keyboard, sound card etc through I/O ports
What operation done by processor for I/O ports and what processes done by I/O ports
read and write
IBM based processor (IAPAX88) takes memory address base and peripheral address base separate. True or false
True
What is memory mapped I/O
There are some processor who takes peripheral address base inside memory address base. They are called memory mapped IO.
What is the size of IAPAX88 address bus
20 bits
What are instructions for read and write port
In = read Out = Write
AX for what
byte
AL for what
Word
Which register holds port address
DX
