21. Which of the following can be a paired set of 16-bit registers?
A. CD
B. HL
C. AB
D. EH
Answer: B
Registers B, C, D, E, H, and L are 8-bit general-purpose registers that can be concatenated to produce 16 registers known as BC, DE, and HL.
22. Which signal is used to differentiate the access from a normal memory cycle?
A. HALT
B. RESET
C. MREQ
D. IORQ
Answer: D
The IORQ signal is used to differentiate the access from a normal memory cycle. These input/output accesses are similar from a hardware perspective to a memory cycle but only occur when an input/output port instruction is executed.
23. What is done in mode1 of Z80?
A. Interrupt vector is supplied via the external bus
B. Interrupt vector is supplied via the peripherals
C. NMI gets started
D. Interrupt gets acknowledged by peripheral
Answer: A
In mode 1, the interrupt vector is supplied via the external data bus. The memory refresh register is used to control the on-chip DRAM refresh circuitry.
24. What does the m1 signal in Z80 describes?
A. I/O operation status
B. Memory refresh output
C. Output pulse on instruction fetch cycle
D. Interrupt request input
Answer: C
It is a signal which describes the output pulse on the instruction fetch cycle. Interrupt request input, input/output operation status, and memory refresh output are the other signals in Z80 for various operations.
25. Which memory storage is widely used in PCs and Embedded Systems?
a) EEPROM
b) Flash memory
c) SRAM
d) DRAM
Answer: d
DRAM is used in PCs and Embedded systems because of its low cost. SRAM, flash memory, and EEPROM are more costly than DRAM.
26. How is the protection and security for an embedded system made?
a) Security chips
b) Memory disk security
c) IPR
d) OTP
Answer: c
Intellectual property right provides security and protection to embedded systems.
27. Which of the following task swapping method is a better choice in the embedded systems design?
a) time slice
b) RMS
c) cooperative multitasking
d) pre-emptive
Answer: d
The pre-emptive method of task swapping is the first choice for embedded system design because of its better system response.
28. Which type of memory is suitable for low volume production of embedded systems?
a) Non-volatile
b) RAM
c) Volatile
d) ROM
Answer: a
The devices which use non-volatile memory allow the software to be downloaded and returned to the device. UV erasable EPROM is favorable but EEPROM is also gaining favor. Therefore, this type of memory is used in low volume production.
29. Which activity is concerned with identifying the task at the final embedded systems?
a) scheduling
b) task-level concurrency management
c) high-level transformation
d) compilation
Answer: b
There are many design activities associated with the platforms in the embedded system and one such is the task-level concurrency management which helps in identifying the task that needed to be present in the final embedded systems.
30. Which level simulates the algorithms that are used within the embedded systems?
a) algorithmic level
b) switch level
c) gate level
d) circuit level
Answer: a
The algorithmic level simulates the algorithm which is used within the embedded system.
