Question

What type of bit in the ARM memory mimics to that of the protection unit of ARM management unit?

(a) permission bit

(b) buffer bit

(c) cacheable bit

(d) access permission bit

The question was posed to me in a national level competition.

The doubt is from Memory Protection Unit in chapter Memory Systems of Embedded Systems

Answer 1

Correct answer is (a) permission bit

For explanation: The ARM architecture memory protection unit divides the memory range into different regions of size ranging from 4 Kbytes to 4 Gbytes. Each region is associated with certain bits called the cacheable bit, buffer bit, and access permitted bit. These bits are similar to the permission bit in the ARM memory management unit architecture which is stored in the control register.