a) Program counter (PC) – Program is a sequence of instructions. As mentioned earlier, microprocessor fetches these instructions from the memory and executes them The program counter is a
special purpose register
which, at a given time,stores the address of the next instruction to be fetched.
Which of the following is not considered as special purpose register?
5. Which of the following is not a special function register? Explanation:
Accumulator is a general function register
, which can be used for multiple functions. Explanation: SP is the short form of stack pointer which store address of stack top.
What are the types of special purpose registers?
- I/O and peripheral control (such as serial ports or general-purpose IOs)
- timers.
- stack pointer.
- stack limit (to prevent overflows)
- program counter.
- subroutine return address.
- processor status (servicing an interrupt, running in protected mode, etc.)
- condition codes (result of previous comparisons)
Which register is a special purpose register?
The flag register
is a special purpose register and it is completely different from other registers in microprocessor. It consists of 8 bits and only 5 of them are useful.
Is program counter a special purpose register?
a) Program counter (PC) – Program is a sequence of instructions. As mentioned earlier, microprocessor fetches these instructions from the memory and executes them The program counter is a
special purpose register
which, at a given time,stores the address of the next instruction to be fetched.
What is the purpose of IP registers?
A special-purpose register, usually called the instruction pointer (IP) or program counter (PC),
keeps track of what instruction is being executed.
What is the purpose of registers?
In Computer Architecture, the Registers are very fast computer memory which are
used to execute programs and operations efficiently
. This does by giving access to commonly used values, i.e., the values which are in the point of operation/execution at that time.
What are the types of registers?
- MAR Register. The full form of MAR is the memory address register. …
- MDR. The full form of MDR register is a memory data register. …
- MBR. The full form of MBR is the memory buffer register. …
- PC. The full form of PC is the program counter register. …
- Accumulator. …
- Index Register. …
- Instruction Register.
Why are special registers needed?
We have discussed general purpose registers as being discrete memory locations within the CPU used to hold temporary data and instructions. … A special purpose register is
one that has a specific control or data handling task to carry out
. There are a number of special purpose registers within the CPU.
Is accumulator a general purpose register?
Modern computer systems often have
multiple general-purpose registers
that can operate as accumulators, and the term is no longer as common as it once was. However, to simplify their design, a number of special-purpose processors still use a single accumulator.
What are the advantages of general purpose registers?
The advantages of General register based CPU organization –
Efficiency of CPU increases as there are a large number of registers are used in this organization
. Less memory space is used to store the program since the instructions are written in compact way.
Why accumulator is called special register?
| Before After | (4050H) CDH ABH |
|---|
Which register is a 16 bit special purpose register?
Stack Pointer (SP):
It is a 16-bit special purpose register which always stores the address of top of the Stack. i.e. it always points to top of the Stack. Stack is a part of the memory location used to store the data temporarily.
Why program counter is 16 bit register?
The program counter acts
as a pointer to the next instruction to be executed
and always contains the 16-bit address of the memory location of next instruction. It is a 16 bit register as 8085 has 16 address lines.
Which register pair is used to indicate memory?
H and L register pair
is used to act as memory pointer and it holds 16 bit address of memory location.
Do registers have addresses?
Registers do have addresses
, even though they don’t generally reside in memory. Think about it a minute : an address denotes a location in some space, where memory is just one instance of a space.
