How many 16 K × 1 bit RAM chips are needed to provide a memory capacity of 128…

Concept

A memory module has two independent dimensions: address depth and word width. The number of chips is the depth-expansion factor multiplied by the width-expansion factor.

For a target of Dₜ × Wₜ built from D꜀ × W꜀ chips, the chip count is (Dₜ ÷ D꜀) × (Wₜ ÷ W꜀), provided both ratios are whole numbers.

Application

1. Depth expansion: 128 K ÷ 16 K = 8 banks, because each bank covers 16 K addresses.

2. Width expansion: 1 byte = 8 bits, so each bank needs 8 one-bit chips in parallel.

3. Combine the independent factors: 8 banks × 8 chips per bank = 64 chips.

4. Therefore, the required memory organization uses 64 RAM chips.

Cross-check

The target stores 128 K × 8 = 1024 K bits. One chip stores 16 K bits, and 1024 K ÷ 16 K = 64, which confirms the depth-by-width calculation.

Result: 64 RAM chips.