1. The feature of mode 2 of 8255 is
a. single 8-bit port is available
b. both inputs and outputs are latched
c. port C is used for generating handshake signals
d. all of the mentioned
Ans- d. all of the mentioned
2. The signals that are provided to maintain proper data flow and synchronization between the data transmitter and receiver are
a. handshaking signals
b. control signals
c. input signals
d. none
Ans- a. handshaking signals
3. The level of the signal ERROR(active low) becomes 'low' when the printer is in
a. Paper end state
b. Offline state
c. Error state
d. All of the mentioned
Ans- d. All of the mentioned
4. The pulse width of the signal INIT at the receiving terminal must be more than
a. 10 microseconds
b. 20 microseconds
c. 40 microseconds
d. 50 microseconds
Ans- d. 50 microseconds
5. The signal, SLCT in the direction of signal flow, OUT, indicates the selection of
a. Control word register
b. CPU
c. Printer
d. Ports
Ans- c. Printer
6. If the value of the pin STB (Strobe Input) falls to low level, then
a. input port is loaded into input latches
b. input port is loaded into output latches
c. output port is loaded into input latches
d. output port is loaded into output latches
Ans- a. input port is loaded into input latches
7. The strobed input/output mode is another name of
a. mode 0
b. mode 1
c. mode 2
d. none
Ans- b. mode 1
8. The feature of mode 0 is
a. any port can be used as input or output
b. output ports are latched
c. maximum of 4 ports are available
d. all of the mentioned
Ans- d. all of the mentioned
9. In BSR mode, only port C can be used to
a. set individual ports
b. reset individual ports
c. set and reset individual ports
d. programmable I/O ports
Ans- c. set and reset individual ports
10. In the I/O mode, the 8255 ports work as
a. reset pins
b. set pins
c. programmable I/O ports
d. only output ports
Ans- c. programmable I/O ports