2. List the applications of PROM in digital circuit design, considering factors such as flexibility and reprogrammability.

Programmable Read-Only Memory (PROM) is a type of digital memory where the setting of each bit is locked by a fuse or antifuse. It is one-time programmable, unlike other types of programmable ROM such as EPROM and EEPROM which can be reprogrammed multiple times. Here are some applications of PROM in digital circuit design:

1. Firmware Storage: PROM is often used to store firmware in devices, which is the software that allows the device to function. This is a common application in many electronic devices such as computers, game consoles, and mobile phones.

2. Microcode Storage: In computer architecture, PROM can be used to store microcode for the central processing unit (CPU). Microcode is a layer of hardware-level instructions that implement higher-level machine code instructions.

3. Lookup Tables: PROM can be used to implement lookup tables in digital circuits. This is useful in applications where a certain input needs to be quickly mapped to a corresponding output.

4. State Machines: PROM can be used to implement state machines in digital circuits. This is useful in applications where the circuit needs to move through a series of states based on its inputs.

5. Custom Logic Functions: PROM can be used to implement custom logic functions in digital circuits. This is useful in applications where a specific logic function is needed that is not available in standard logic gates.

6. Device Configuration: In some cases, PROM can be used to configure a device at startup. This is useful in applications where the device needs to be configured in a specific way each time it is powered on.

The main advantage of PROM is its flexibility. Since it can be programmed to implement any logic function, it can be used in a wide variety of applications. However, its main disadvantage is that it cannot be reprogrammed. Once a PROM has been programmed, its contents cannot be changed. This makes it less suitable for applications where the logic