A. interrupt
B. function
C. procedure
D. structure
Answer: A
When the port receives the data, it will generate an interrupt which in turn activates the ISR.
22. Which code is written as part of the ISR?
A. data receive code
B. sequential code
C. data transfer code
D. concurrent code
Answer: C
The data transfer codes are written as part of the interrupt service routine which is associated with the interrupt generation by the hardware.
23. Which interrupts are generated by the on-chip peripherals?
A. internal
B. external
C. software
D. hardware
Answer: A
The internal interrupts are generated by the serial and parallel ports which are on-chip peripherals.
24. Which of the following is the common method for connecting the peripheral to the processor?
A. internal interrupts
B. external interrupts
C. software
D. exception
Answer: B
The common method for connecting the peripheral to the processor is the external interrupts. The external interrupts are provided through the external pins which are connected to the peripherals.
25. Which interrupt can make a change in the processor’s mode?
A. internal interrupt
B. external interrupts
C. exceptions
D. software mode
Answer: C
An exception is an event that changes the software flow to process the event. It includes both internal and external interrupts which cause the processor to change to a service routine.
26. How many exceptions does an MC68000 have?
A. 256
B. 128
C. 90
D. 70
Answer: C
The MC68000 has 256 table entries that describe 90 exceptions.
27. Which interrupts allows a protected state?
A. internal interrupt
B. external interrupt
C. software interrupt
D. both internal and external interrupts
Answer: C
The software interrupt can change the processor into a protected state by changing the program flow.
28. How a software interrupt is created?
A. instruction set
B. sequential code
C. concurrent code
D. porting
Answer: A
The software interrupts include a set of instructions for handling interrupts. The instruction set allows a currently executing program to change its flow.
29. What does SWI stand for?
A. standard interrupt instruction
B. sequential interrupt instruction
C. software interrupts instruction
D. system interrupt instruction
Answer: C
The instruction set of software interrupts is provided by the special instruction set. One such is the SWI which is commonly used in Z80.
30. Which of the following use SWI as an interrupt mechanism?
A. PowerPC
B. MC68000
C. Z80
D. IBM PC
Answer: C
The PowerPC and MC68000 use the TRAP instruction set for accessing software interrupt. IBM PC uses 8086 NMI. Z80 uses SWI for accessing software interrupts.