Question

Explain memory register map of 8051 Micro-controller with diagram.

Explain the memory register mapping for 8051 Micro-controller with neat diagram.

Answer 1

1. The 8051 addresses has two separate memory spaces:
   1. Program memory space.
   2. Data memory space.
2. The memory map for the 8051 is illustrated in the following image.
   
3. The program's memory area is read-only memory (ROM).
4. This memory area is meant for storing programs and variable data.
5. The CPU can read program instructions from this memory but not write data to it.
6. All instruction fetches come from the program memory area.
7. The data memory space supports both read and write operations.
8. The processor has the ability to read data from and write to this memory area.
9. It cannot run instructions from this memory section. This memory area contains the internal RAM for the 8051.
10. The internal RAM contains 128 bytes for general read/write data storage. Some of this is due to memory space.
11. The 8051 contains 22 special function registers that are not part of the 128-byte RAM. They occupy memory spaces ranging from 80H to F8H. These registers are utilized for the appropriate purpose.
12. The 4K byte program memory can be increased by an extra 60k bytes, resulting in 64K byte program memory. The data memory can be increased up to 64K bytes.
13. The 8051 can also be used with shared memory. In this example, the 8051 has 64K bytes of total external memory. In this configuration, the 8051 may accept a block of data via its serial communications port, store that data in memory, and then execute it as a program. This is referred to as a downloaded software. It is a relatively frequent technique for changing the program running in a remote microprocessor-based controller.