32位地址16位数据内存容量计算疑问：为何是64G而非8G？

Hey there! Let's clear up this confusion together—your initial calculation is actually correct, so let's break down why there's a discrepancy with your teacher's answer.

First, let's recap the core math for memory capacity:

• Address lines: 32 bits mean we can address 2^32 distinct memory locations (units).
• Data lines: 16 bits mean each addressable unit holds 16 bits, which is equivalent to 2 bytes.

So total capacity in bytes is:

2^32 addresses * 2 bytes/address = 2^33 bytes

Since 1 GB = 2^30 bytes, converting gives:

2^33 / 2^30 = 2^3 = 8 GB

That's exactly what you calculated—you're right on the money here.

Now, why would the teacher say 64 GB? The most likely culprit is a mix-up between bits and bytes in the data line calculation. If someone incorrectly treats 16 bits as 16 bytes instead of 2 bytes, the math becomes:

2^32 addresses * 16 bytes/address = 2^36 bytes = 64 GB

That's the only way to get 64 GB from these numbers, and it's a common mistake when mixing up bit/byte units.

Another slim possibility is a miscommunication about the system's addressing mode—for example, if the memory was using word-addressing where a "word" was incorrectly defined as 64 bits, but that doesn't align with the given 16-bit data line.

Bottom line: Your calculation is correct, and the 64 GB answer likely stems from a unit conversion error.

内容的提问来源于stack exchange，提问作者AznBoyStride