Correct Answer - Option 1 : 16
Data Pointer (DTPR):
- DPTR is meant for pointing to data. It is the 8051’s only user-accessible 16-bit (2-byte) register.
- The accumulator, R0–R7 registers and B register are 1-byte value registers.
- It is used by the 8051 to access external memory using the address indicated by DPTR.
- DPTR is the only 16-bit register available and is often used to store 2-byte values.
Program Counter (PC):
Program Counter (PC) is a 2-byte address which tells the 8051 where the next instruction to execute can be found in the memory.
Stack Pointer (SP):
- It hold an 8-bit (1-byte) value. It tells the location from where the next value is to be removed from the stack.
- When a value is pushed onto the stack, the value of SP is incremented and then the value is stored at the resulting memory location.
- When a value is popped off the stack, the value is returned from the memory location indicated by SP, and then the value of SP is decremented.