Can anyone please explain what is the meaning of representing RAM chip in a format like 2K x 4. What are the information about the chip we get from such a representation.
1 Answer
The format (i.e. 2K x 4 or 1M x 1) tells you something about the memory chips' organization.
The first number (usually the larger number) represents the number of individually addressable units (addresses) and the second number represents the number of bits that are read or written in parallel per addressable unit.
For example, a 2K x 4 chip (if it exists) would have 2K = 2048 = 2^11 addresses and can write or read 4 bits at a time. This also means this chip would have 11 address lines (maybe multiplexed for a smaller number of external pins) and 4 data lines (the bits that are written or read). To be used in a system that processes 8 bits at a time (like an early home computer), you would need 2 chips in parallel, each providing 4 of the 8 bits.
A 1M x 1 chip would address 2^20 individualy adressable bits and would usually have a multiplexed address bus to reduce the number of external pins needed on the chip. On a computer with a 32-bit data bus, you would need at least 32 of these working in parallel, each providing 1 of the 32 data bits.
