How is access control to memory cells implemented in a system?

Access control to memory cells in the system is implemented through several methods:

1. Hardware mechanisms — the processor and memory support access levels (for example, user and privileged modes), as well as memory page protection (Memory Protection Unit, MMU), which prohibits or allows reading, writing, and executing code in certain memory regions.

2. Operating system — manages virtual memory, assigns access rights to memory pages for processes, isolates processes from each other, preventing unauthorized access.

3. Software methods — using programming languages with managed memory (for example, Python, Java), where memory access is controlled by the runtime environment.

4. Hardware security features — such as Intel SGX or ARM TrustZone technologies, provide protected memory areas.

Thus, access control is implemented at multiple levels to ensure the security and stability of the system.