Which type of RAM does not required refreshing circuit?

Question

Examoogle · Accepted Answer

Static RAM

Explanation: Static RAM (SRAM) does not require a refreshing circuit because it uses a bistable latching circuit, typically consisting of 6 transistors per cell, to hold data. In contrast, Dynamic RAM (DRAM) stores data as a charge in a capacitor, which naturally leaks over time, necessitating periodic refreshing.

Working Principle: SRAM uses flip-flop configurations (typically 6T architecture) to maintain state. As long as power is supplied, the cross-coupled inverters continuously reinforce the logic state ('0' or '1'). Because it does not rely on capacitive charge storage, there is no decay process and thus no need for external hardware refresh cycles.

Key Formulas: $T_{refresh} \approx 0$ — Refresh time required for SRAM; $Q = C \cdot V$ — Charge storage principle requiring refresh in DRAM

Key Points: SRAM cells consist of a cross-coupled inverter pair.; Data is volatile and lost when power is removed, but stable while powered.; SRAM is significantly faster than DRAM due to the lack of refresh delays.; DRAM requires a periodic refresh cycle to prevent charge leakage loss.

Advantages: Higher speed (lower access time); No refresh circuitry complexity; Lower power consumption at low frequencies

Disadvantages: Higher cost per bit; Lower storage density due to 6T cell size; Requires larger chip area

Applications: CPU Cache memory (L1, L2, L3); High-speed registers

Additional Info: DRAM uses a '1T-1C' structure which is compact but leaky, hence the refreshing.. Option A is incorrect because Dynamic RAM is defined specifically by its requirement to be refreshed.

Answer: B is correct — Static RAM uses bistable flip-flop logic to retain state, eliminating the need for periodic refreshing circuits required by DRAM.

Exam Tip: In competitive exams, remember that DRAM is 'cheap and dense' (high capacity) while SRAM is 'fast and complex' (high performance).

Related Questions

Discussion (0)