1. In memory-mapped scheme, the devices are viewed as
a. distinct I/O devices
b. memory locations
c. only input devices
d. only output devices
Ans- b. memory locations
2. In 74LS245, if DIR is 1, then the direction is from
a. inputs to outputs
b. outputs to inputs
c. source to sink
d. sink to source
Ans- a. inputs to outputs
3. The chip 74LS245 is
a. bidirectional buffer
b. 8-bit input port
c. one that has 8 buffers
d. all of the mentioned
Ans- d. all of the mentioned
4. To avoid loading during read operation, the device used is
a. latch
b. flipflop
c. buffer
d. tristate buffer
Ans- d. tristate buffer
5. While performing read operation, one must take care that much current should not be
a. sourced from data lines
b. sinked from data lines
c. sourced or sinked from data lines
d. sinked from address lines
Ans- c. sourced or sinked from data lines
6. The latch or IC 74LS373 acts as
a. good input port
b. bad input port
c. good output port
d. bad output port
Ans- c. good output port
7. The operation, IOWR (active low) performs
a. write operation on input data
b. write operation on output data
c. read operation on input data
d. read operation on output data
Ans- b. write operation on output data
8. The input and output operations are respectively similar to the operations,
a. read, read
b. write, write
c. read, write
d. write, read
Ans- c. read, write
9. The example of output device is
a. CRT display
b. 7-segment display
c. Printer
d. All of the mentioned
Ans- d. All of the mentioned
10. The device that enables the microprocessor to read data from the external devices is
a. printer
b. joystick
c. display
d. reader
Ans- b. joystick