In protected mode of the 80286 microprocessor, there are two types of registers available: index registers and segmented registers. Let's explore each of these register types in detail:

Index Registers:
- Index registers are used for addressing memory operands in protected mode.
- The 80286 provides four index registers: BP (base pointer), DI (destination index), SI (source index), and SP (stack pointer).
- These registers are 16 bits wide, allowing them to hold values ranging from 0 to 65535.
- The BP register is typically used as a base pointer for accessing parameters and local variables within a function.
- The DI and SI registers are commonly used for string operations, such as copying or comparing strings.
- The SP register is used to keep track of the top of the stack.

Segmented Registers:
- Segmented registers are used to store segment selectors, which are used for memory segmentation in protected mode.
- The 80286 provides four segmented registers: CS (code segment), DS (data segment), SS (stack segment), and ES (extra segment).
- Each segmented register is 16 bits wide and can hold a segment selector value.
- The CS register stores the segment selector for the currently executing code segment.
- The DS register is used for accessing data in memory.
- The SS register points to the stack segment, which contains the runtime stack.
- The ES register is an extra segment register that can be used for additional data storage.

In protected mode, memory addressing is done using a combination of segment selectors and offset values. The segmented registers hold the segment selector values, while the index registers are used to hold the offset values. Together, they allow for efficient memory addressing and manipulation.

Overall, the combination of index registers and segmented registers in protected mode provides greater flexibility and efficiency in memory management and addressing compared to real mode.