Digital Electronics Objectives Part 18
341 . 119 times program jump to the LOOP.
342 . The program can be changed to loop 210 times by changing first instruction to MVICD211.
343 . Interaction between a CPU and a peripheral device that takes place during an I/O operation is known as handshaking.
344 . Addressing in which the location of the data is contained within the mnemonic is knows as implied addressing.
345 . Addressing in which the instruction contains the address of the data to be operated on, is known as direct addressing.
346 . Match the following.
Column I Column II
(a) Pop (i) to save data in the stock
(b) Push (ii) to read data from the stack
(c) Stack (iii) a portion of memory reserved for return addresses and data
(d) Mask (iv) a byte used with an ANI instruction to blankout certain bits
a—(ii), b—(i), c—(iii), d—(iv)
347 . A floppy disc is a thin plastic disc coated with magnetic oxide.
348 . Interrupt-driven I/O is a type of I/O transfer that both hardware and software.
349 . Restart is special type of CALL in which the address is not programmed but built into the hardware.
350 . 8085 has 8 software restarts and 4 hardware restarts.
351 . Serial input data of 8085 can be loaded into bit 7 of the accumulator by executing a RIM instruction.
352 . In 8085, TRAP is used for catastrophic events like temporary power failure.
353 . The address to which a software or hardware restart branches is known as vector location.
354 . Vectored interrupt is an interrupt that takes the program to a vector location, TRAP vectors to 0024 H, RST 7.5 to 003 CH, RST 6.5 to 0034 H and RST 5.5 to 003 CH.
355 . In 8085 usually the vector location and the next two memory location contain a JMP instruction. This allows the program to branch to a longer sub-routine.
356 . TRAP is non-maskable where RST 7.5. RST 6.5, RST, 5.5 are maskable.
357 . In 8085, to disable the whole interrupt system(except TRAP) the DI instruction may be used.
Question 358 to 361 refer to data given below:
RIM
EI
RET
Suppose the accumulator contains CAH after the RIM is executed.
358 . Serial input data is high.
359 . 7.5 are pending interrupts.
360 . Interrupt-enable flag is high.
