Understanding ROM Composition
ROM, or Read-Only Memory, is a crucial component in digital electronics, primarily used for storing firmware or permanent data. The correct answer to the question regarding its composition is option 'C': Decoder and OR gates.
Key Components of ROM:
- Decoder:
- A decoder is a combinational circuit that converts binary information from n input lines to a maximum of 2^n unique output lines.
- In ROM, the decoder is essential for selecting memory locations based on the binary address input.
- It ensures that only one specific memory location is accessed during a read operation.
- OR Gates:
- OR gates are used in conjunction with the outputs from the decoder to retrieve data stored in the ROM.
- The OR gate combines the outputs of the selected memory cells, allowing the desired data to be output as a single line.
- This functionality is vital as it enables the output of multiple bits of data from different memory cells simultaneously.
Why Not Other Options?
- NAND and OR Gates:
- While NAND gates are used in various logic circuits, they do not specifically function as address decoders in ROM.
- NOR and Decoder:
- NOR gates are similarly not employed to retrieve data from ROM; rather, they are logic gates used for different logical operations.
- NAND and Decoder:
- This combination does not accurately describe the typical architecture of ROM, as NAND gates alone cannot perform the required data output functions.
Conclusion:
The combination of a decoder and OR gates forms the fundamental architecture of ROM, allowing for efficient data access and retrieval. Understanding these components is essential for anyone studying electronics and communication engineering.