- Semiconductor memories are pivotal electronic data storage devices leveraging semiconductor technology to encode and retrieve digital information. Typically, they utilize metal-oxide-semiconductor (MOS) memory cells integrated into silicon chips.
- Within these chips, each bit of binary data is stored within minute circuits known as memory cells, often composed of multiple transistors. These cells are arranged in rectangular arrays across the chip’s surface.
- Data is organized into small units called words, with each word accessed as a single memory address. The word length is typically a power of two, denoted by N (e.g., 1, 2, 4, or 8 bits). Accessing data is facilitated by applying a binary number, termed a memory address, to the chip’s address pins, specifying the target word. If the memory address has M bits, the chip can accommodate 2^M addresses, each containing an N-bit word. Consequently, the total data storage capacity of the chip is N * 2^M bits.
- This storage capacity, often measured in kilobits, megabits, gigabits, or terabits, scales with the number of address lines, typically in powers of two (e.g., 2, 4, 8, 16, 32, 64, 128, 256, and 512). As the demand for faster memories grows, various types of semiconductor memories have emerged to meet diverse requirements.
- The two different types of memories are Volatile memory (holds the data only when the device is on) and Non-volatile memory (holds data even when the device is off).
- Below figure shows detailed classification of semiconductor memories:
