This set of Digital Electronics/Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Programmable Read Only Memory -1”.
1. The time from the beginning of a read cycle to the end of tACS/tAA is called as ____________
a) Write enable time
b) Data hold
c) Read cycle time
d) Access time
Explanation: The time from the beginning of a read cycle to the end of tACS/tAA is called as access time. It is the time in which data is fetched from the storage.
2. Why did PROM introduced?
a) To increase the storage capacity
b) To increase the address locations
c) To provide flexibility
d) To reduce the size
Explanation: In order to provide some flexibility in the possible applications of ROM, PROM is introduced. PROM stands for Programmable ROM, in which the ROM is programmed by the user.
3. Which of the following is programmed electrically by the user?
Explanation: Programmable ROMs can be programmed electrically by the user but can’t be reprogrammed. EEPROMs can be electrically erased and re-programmed by the user.
4. PROMs are available in ___________
a) Bipolar and MOSFET technologies
b) MOSFET and FET technologies
c) FET and bipolar technologies
d) MOS and bipolar technologies
Explanation: PROMs (Programmable ROMs) can be programmed electrically by the user but can’t be reprogrammed. PROMs are available in both bipolar and MOS (Metal Oxide Semiconductor) technologies.
5. The bit capacity of a memory that has 2048 addresses and can store 8 bits at each address is ___________
Explanation: 1 address can store 8 bits. Therefore, total capacity of a memory having n addresses = 8 * n.
Therefore, for 2048 addresses,
total capacity of a memory = 2048 * 8 = 16384 bits.
6. How many 8 k × 1 RAMs are required to achieve a memory with a word capacity of 8 k and a word length of eight bits?
Explanation: RAM stands for Random Access Memory in which any memory address can be accessed in any order. It requires word of length 8 bits. So, one word needs of 1 bit and 8 bit requires 8 bits.
7. Which of the following best describes the fusible-link PROM?
a) Manufacturer-programmable, reprogrammable
b) Manufacturer-programmable, one-time programmable
c) User-programmable, reprogrammable
d) User-programmable, one-time programmable
Explanation: The fusible-link PROM is user programmable and one time programmable. It means that a written program can not be reprogrammed. EPROMs can be erased and re-programmed.
8. How can ultraviolet erasable PROMs be recognized?
a) There is a small window on the chip
b) They will have a small violet dot next to the #1 pin
c) Their part number always starts with a “U”, such as in U12
d) They are not readily identifiable, since they must always be kept under a small cover
Explanation: An ultraviolet erasable PROMs have small window on the chip with black marked. Such type of PROMS are called EPROMS which are cleared by exposing it to UV radiation. They are re-programmable.
9. Which part of a Flash memory architecture manages all chip functions?
a) Program verify code
b) Floating-gate MOSFET
c) Command code
d) Input/Output pins
Explanation: MOSFET technology is the best one in the manufacturing of chip because it has high flexibility and storage capacity. Thus, Floating-Gate MOSFET part of a Flash Memory architecture manages all chip functions.
10. How much locations an 8-bit address code can select in memory?
a) 8 locations
b) 256 locations
c) 65,536 locations
d) 131,072 locations
Explanation: An 8 bit address code requires 32 memory locations and it can hold maximum upto 32 * 8 = 256 locations = 28.
11. What is a fusing process?
a) It is a process by which data is passed to the memory
b) It is a process by which data is read through the memory
c) It is a process by which programs are burnout to the diode/transistors
d) It is a process by which data is fetched through the memory
Explanation: Fusing is a process by which programs are burnout to the diode/transistors and it can not be reprogrammed if any error occurs.
12. Fusing process is ___________
Explanation: Since, any program cannot be reprogrammed in a PROM, so this process is irreversible as PROMs are programmed using the Fusing process. Fusing is a process by which programs are burnout to the diode/transistors and it can not be reprogrammed if any error occurs.
13. The cell type used inside a PROM is ___________
a) Link cells
b) Metal cells
c) Fuse cells
d) Electric cells
Explanation: The cell type used inside a PROM is fuse cells by which a program is burnout. Fusing is a process by which programs are burnout to the diode/transistors and it can not be reprogrammed if any error occurs.
14. How many types of fuse technologies are used in PROMs?
Explanation: Fusing is a process by which programs are burnout to the diode/transistors and it can not be reprogrammed if any error occurs. Three types of fuse technologies are used in PROMs and these are: (i) Metal links, (ii) Silicon links, & (iii) p-n junctions.
15. Metal links are made up of ___________
b) Magnesium sulphide
d) Silicon dioxide
Explanation: Metal links are made up of Nichrome materials.
Sanfoundry Global Education & Learning Series – Digital Circuits.
To practice all areas of Digital Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.