Embedded System Questions and Answers Part-20

1. Which of the following can transfer up to 1.6 billion bytes per second?
a) DRAM
b) RDRAM
c) EDO RAM
d) SDRAM

Answer: b
Explanation: The Rambus RAM can transfer up to 1.6 billion bytes per second. It possesses RAM controller, a bus which connects the microprocessor and the device, and random access memory.

2. Which of the following cycle is larger than the access time?
a) write cycle
b) set up time
c) read cycle
d) hold time

Answer: c
Explanation: The read cycle in the DRAM interfacing is larger than the access time because of the precharge time.

3. Which mode of operation selects an internal page of memory in the DRAM interfacing?
a) page interleaving
b) page mode
c) burst mode
d) EDO RAM

Answer: b
Explanation: In the page mode operation, the row address is provided as normal but the RAS signal is left asserted. This, in turn, selects an internal page within the DRAM memory where any bit of data can be accessed by placing the column address and asserting CAS.

4. What is the maximum time that the RAS signal can be asserted in the page mode operation?
a) 5 microseconds
b) 10 microseconds
c) 15 microseconds
d) 20 microseconds

Answer: b
Explanation: The maximum time that the RAS signal can be asserted during the page mode operation is about 10 microseconds. But this is a major disadvantage for page mode operation, that is, the standard PCs have a maximum time of 15 microseconds for the refresh cycle.

5. Which of the following mode of operation in the DRAM interfacing has a page boundary?
a) burst mode
b) EDO RAM
c) page mode
d) page interleaving

Answer: c
Explanation: The page mode operation have memory cycles that exhibit some form of locality, that is, stay within the page boundary which causes page missing when there is access outside the page boundary and two or more wait states.

6. Which mode offers the banking of memory in the DRAM interfacing technique?
a) page mode
b) basic DRAM interfacing
c) page interleaving
d) burst mode

Answer: c
Explanation: The accessing of data outside the page boundary can cause missing of pages in the page mode operation. So a program has to operate for frequently accessing data thereby, increasing the efficiency in the page selection. One such mode is the page interleaving mode in which the memory is divided into different banks, depending on the number of memories installed.

7. Which of the following has a fast page mode RAM?
a) burst mode
b) page interleaving
c) EDO memory
d) page mode

Answer: c
Explanation: Extended data out memory is a fast page mode RAM which has a faster cycling process which makes EDO memory a faster page mode access.

8. Which mode reduces the need for fast static RAMs?
a) page mode
b) page interleaving
c) burst mode
d) EDO memory

Answer: c
Explanation: The page mode, nibble mode devices can provide data fastly when the new column address is given. In burst mode operation, the processor can fetch more data than it needs and keeps the remaining data in an internal cache for the future use which can reduce the need for fast static RAMs.

9. Which of the following is also known as hyper page mode enabled DRAM?
a) page mode
b) EDO DRAM
c) burst EDO DRAM
d) page interleaving

Answer: b
Explanation: The EDO DRAM is also known as hyper page mode enable DRAM because of the faster page mode operation along with some additional features.

10. What does BEDO DRAM stand for?
a) burst EDO DRAM
b) buffer EDO DRAM
c) BIBO EDO DRAM
d) bilateral EDO DRAM

Answer: a
Explanation: The burst EDO DRAM is evolved from the EDO DRAM and it can access four memory addresses in one burst. It also supports pipeline stages which allow the page access cycle into two parts.