Interrupt
Q1.
A keyboard connected to a computer is used at a rate of 1 keystroke per second. The computer system polls the keyboard every 10 ms (milli seconds) to check for a keystroke and consumes 100 \mu s (micro seconds) for each poll. If it is determined after polling that a key has been pressed, the system consumes an additional 200 \mu s to process the keystroke. Let T_1 denote the fraction of a second spent in polling and processing a keystroke. In an alternative implementation, the system uses interrupts instead of polling. An interrupt is raised for every keystroke. It takes a total of 1 ms for servicing an interrupt and processing a keystroke. Let T_2 denote the fraction of a second spent in servicing the interrupt and processing a keystroke. The ratio \frac{T_1}{T_2} is ______ . (Rounded off to one decimal place)Q4.
An interrupt in which the external device supplies its address as well as the interrupt requests is known asQ7.
RST 7.5 interrupt in 8085 microprocessor executes the interrupt service routing from interrupt vector locationQ8.
Consider the following statements. I. Daisy chaining is used to assign priorities in attending interrupts. II. When a device raises a vectored interrupt, the CPU does polling to identify the source of interrupt. III. In polling,the CPU periodically checks the status bits to know if any device needs its attention. IV. During DMA, both the CPU and DMA controller can be bus masters at the same time. Which of the above statements is/are TRUE?Q9.
Choose the correct alternatives (more than one may be correct) and write the corresponding letters only: The TRAP interrupts mechanism of the 8085 microprocessor: