Question

Which of the following memories requires periodic refreshing to maintain stored data?

• A. Flash
• B. Cache
• C. Dynamic RAM (DRAM)
• D. EPRAM

Hint:

Remember:
• DRAM = Dynamic = Requires Refreshing.
• SRAM = Static = No Refresh Required.
• Flash Memory = Non-volatile.

Answer 1

The Correct Option is C

Concept: Dynamic Random Access Memory (DRAM) is a type of volatile semiconductor memory used as the main memory in computers. It stores each bit of data in a capacitor, but the electrical charge stored in the capacitor gradually leaks away. Therefore, the stored data must be refreshed periodically to prevent data loss.
• DRAM is volatile memory.
• Data is stored using capacitors.
• Requires periodic refreshing to retain information.
• Widely used as the primary memory (RAM) in computers.

Step 1: Understand why refreshing is required.
Each memory cell in DRAM stores data as an electric charge. Since the charge gradually decreases with time, the memory controller must periodically recharge (refresh) every memory cell. \[ \boxed{\text{Without refreshing, the stored data will be lost.}} \]

Step 2: Compare the given memory types.

• Flash Memory -- Non-volatile memory; does not require refreshing.
• Cache Memory -- Usually built using SRAM, which does not require refreshing.
• Dynamic RAM (DRAM) -- Requires periodic refreshing. (Correct)
• EPRAM -- Programmable memory; does not require periodic refresh.

Step 3: Differentiate DRAM and SRAM.

• DRAM stores data in capacitors and requires refreshing.
• SRAM stores data using flip-flops and does not require refreshing.
• DRAM is slower but cheaper and has higher storage capacity.
• SRAM is faster but more expensive.

Step 4: Final conclusion.
Hence, the memory that requires periodic refreshing is: \[ \boxed{\text{Dynamic RAM (DRAM)}} \]