21. Which is the concatenated register of MC68HC11?
A. D
B. X
C. IP
D. DI
Answer: A
The MC68HC11 architecture is similar to that of the 6800 and has two 8-bit accumulators referred to as registers A and B. They are concatenated to provide a 16-bit double accumulator called register D.
22. What does CCR stand for?
A. Condition code register
B. Computing code register
C. Complex code register
D. Code control register
Answer: A
Condition code register is a special register in the MC68HC11.
23. How many bytes of EPROM does MC68HC7054A possess?
A. 176 bytes
B. 240 bytes
C. 4144 bytes
D. 1024 bytes
Answer: C
There are defined memory sizes for different processors and controllers. The MC68HC705A has 4144 bytes of EPROM.
24. Which of the following is an 8-bit command in MC68HC11?
A. Add
B. Shift
C. Multiply
D. Subtract
Answer: C
Multiplying two 8-bit requires a 16-bit register.
25. In the below diagram, identify the register of MC68HC05
A. CCR
B. PC
C. SP
D. IV
Answer: A
MC68HC05 has different registers such as the accumulator, stack pointer, and index register. Condition code register has to carry flag, zero flags, negative flag, interrupt flag, and Half carry flag.
26. Which one of the following is an asynchronous communication channel?
A. SPI
B. MUDs
C. MOO
D. VOIP
Answer: A
MOO, MUDs, and VOIP are apps for the online conference which is synchronous but SPI is an asynchronous communication channel.
27. Which of the following microprocessor is designed by Zilog?
A. Z80
B. Zigbee
C. 80386
D. 8087
Answer: A
Designed by Zilog in 1976. 80386 and 8087 are the processors designed by Intel and Zigbee is IEEE based which is used for high-level communication protocol.
28. Z80 is mainly based on
A. Intel 8080
B. MIPS
C. TIMS
D. 8051
Answer: A
Its architecture is based on Intel 8080 but has an extended instruction set and hardware improvement.
29. Flag register of Z80 is also known as
A. Program status register
B. Program status address
C. Program status word
D. Program address register
Answer: C
The flag register of Z80 contains status information such as carry, overflow, signed, etc.
30. What are the two register sets used in Z80?
A. C’D’ and BC’
B. CD and BD
C. IV and MR
D. Main and alternate
Answer: D
Z80 has two sets of registers which are the main registers and alternate registers.