What is the work of a control bus in a processor

 1. The control bus takes care of the logistics of data and commands 

2. It controls the direction of data 

3. Determines which element and when will it send data on the data bus

4. Carries the timing and control signals

What is NVIC

 NVIC or Nested vector interrupt controller is used for

1. Controlling the interrupt traffic that comes to the controller 

2. The configuration of external interrupts 

3. Enabling , Disabling and pending interrupts

4. Priority and Priority grouping can also be done by the NVIC

5. Preempting a low priority interrupt when a high priority interrupt arrives

What is a memory map

1. A file that contains mapping of different regions in the addressable memory location range.

2. Memory maps are fixed in the processor designs.

3. Explains the mapping of various peripheral registers.

4. Processor addressable memory ranges depend on the size of the address bus.

What is a Reset handler

 A Reset handler is a program or a assembly function that carries out all the required initialisations before calling the main function 

The Reset handler is implemented in the Startup file of the code.

What is the difference between RISC and CISC architecture

CISC	RISC
Complex in instruction set	Reduced instruction set
Large instruction set	Modest instruction set
Memory access is available to most instructions	Memory access is only to load and store instructions
Has few registers	Has a large number of registers
More addressing modes	limited addressing modes
instructions are encoded at varied length	instructions are encoded at fixed length
Microcode control logic i.e. non-volatile memory holds logic codes that implement the instructions	Control logic is hard wired using logic gates that is more efficient
Examples intel core	Example ARM