What is the difference between program counter and stack pointer?
What is the difference between program counter and stack pointer?
In conclusion, the main difference between stack pointer and program counter is that the stack pointer is a register that stores the address of the last program request in a stack while the program counter is a register that stores the address of the next instruction to be executed from the memory.
What is the function of stack pointer and program counter?
The Stack Pointer register will hold the address of the top location of the stack. And the program counter is a register always it will hold the address of the memory location from where the next instruction for execution will have to be fetched.
What is a stack pointer in 8051 microcontroller?
The stack pointer on the classic 8051 accesses internal data memory only. The Cx51 Compiler locates the stack area immediately following all variables in the internal data memory. The stack pointer accesses internal memory indirectly and can use all of the internal data memory up to the 0xFF limit.
What is the size of stack pointer and program counter in 8051?
Why does the stack pointer holds only 8 bit address in 8051 and whereas the program counter holds the 16 bit address? that is the way it was designed. It has only 128 bytes of RAM, so an 8-bit stack pointer is enough.
What is the difference between stack pointer and frame pointer?
The stack pointer always points to the top (or bottom, if you prefer) of the stack. The frame pointer always points to the frame. Stack operations (e.g., push, pop, call) do not modify the frame (in a properly operating system) or the frame pointer (ever).
What is the difference between PC and DPTR?
The PC is pointing to the current instruction, so a PC-relative address would be useful for a nearby lookup table. On the other hand, the DPTR can be set independently to point to an arbitrary location in ROM, not necessarily near the program counter, so you can address locations not within [PC, PC + 256).
What is the function of program counter?
A program counter is a register in a computer processor that contains the address (location) of the instruction being executed at the current time. As each instruction gets fetched, the program counter increases its stored value by 1.
What is timer and counter in 8051?
The 8051 has two timers, Timer 0 and Timer 1. They can be used as timers or as event counters. Both Timer 0 and Timer 1 are 16-bit wide. Since the 8051 follows an 8-bit architecture, each 16 bit is accessed as two separate registers of low-byte and high-byte.
Why do we use stack pointer?
The stack pointer is mainly used as a memory pointer which specifies to the memory location that read and write memory to that location. The typical usage of the stack pointer is to hold stack bits that belong to the present function.
What is a stack frame and how do you use it in a programming stack?
A stack frame is a memory management technique used in some programming languages for generating and eliminating temporary variables. In other words, it can be considered the collection of all information on the stack pertaining to a subprogram call. Stack frames are only existent during the runtime process.
What is ESP and EBP?
The register ‘ESP’ is used to point to the next item on the stack and is referred to as the ‘stack pointer’. EBP aka the ‘frame pointer’ serves as an unchanging reference point for data on the stack. This allows the program to work out how far away something in the stack is from this point.
What is program counter function?
What is difference between link register and program counter?
When a subroutine is called, the return address is stored in the link register. The program counter is the current program address. This register can be written to control the program flow. These registers have special functions and can be accessed only by special instructions.
What is stack pointer function?
A stack pointer is a small register that stores the address of the last program request in a stack. A stack is a specialized buffer which stores data from the top down. As new requests come in, they “push down” the older ones.
What is content of stack pointer?
The Stack Pointer contains the address of the top element of data stored in the stack. A stack can be defined as a container in which insertion and deletion can be done from the one end known as the top of the stack.
How many counters are there in 8051?
8051 microcontrollers have two timers/counters which work on the clock frequency. Timer/counter can be used for time delay generation, counting external events, etc.
What is the difference between clock and timer in microcontroller?
1. The Internal Clock is the counter which counts from 0 to the MCU’s CPU frequency in 1 second (so from 0 to 16 million in my case). 2. The Timer is the same thing as the Internal Clock; it counts up to the CPU frequency in 1 second in sync with the Internal Clock and these terms are used interchangeably.
What is the use of program counter?
Where is stack pointer?
The stack pointer always points to the item that is currently at the top of the stack. A push operation pre-decrements the stack pointer before storing an item on the stack. Hence the program initializes the stack pointer to point one item beyond the highest numbered element in the array that makes up the stack.
What is the difference between a stack pointer and a frame pointer?