Question

A 128 kbyte memory is to be realized using memory chips each with 8 address lines and 4 data lines. Number of memory chips required is ________.

• A. 256
• B. 1024
• C. 128
• D. 512

Hint:

Always convert memory units into bits before calculation. Multiply by 8 for bits and divide by chip capacity to find total number of chips.

Answer 1

The Correct Option is B

Step 1: Determine total bits required \[ 128 \text{ kB} = 128 \times 1024 \text{ bytes} = 131072 \text{ bytes} \] \[ \Rightarrow 131072 \times 8 = 1048576 \text{ bits} \] Step 2: Capacity of one chip
8 address lines $\Rightarrow 2^8 = 256$ addresses
4 data lines $\Rightarrow$ each address holds 4 bits
So, one chip can store $256 \times 4 = 1024$ bits
Step 3: Number of chips required
\[ \frac{1048576 \text{ bits}}{1024 \text{ bits/chip}} = 1024 \text{ chips} \]