Table of Contents
What is program status word register?
The program status word (PSW) is a register that performs the function of a status register and program counter, and sometimes more. The term is also applied to a copy of the PSW in storage.
What is status word microprocessor?
processor status word (PSW) A word that describes fully the condition of a processor at each instant. It indicates which classes of operations are allowed and which are forbidden, and the status of all interrupts associated with the processor.
What is purpose of PSW?
PSW’s provide personal care and related paraprofessional services in accordance with an established plan of care. They are typically involved in both personal care tasks and incidental activities of daily living such as housekeeping, meal preparation, socialization, and companionship.
What is Program Counter 8051?
The Program Counter (PC) is a 2-byte address which tells the 8051 where the next instruction to execute can be found in the memory. PC starts at 0000h when the 8051 initializes and is incremented every time after an instruction is executed.
What is Programme status?
program status word (PSW) A collection of information that encapsulates the basic execution state of a program at any instant. It permits an interrupted process to resume operation after the interrupt has been handled.
What is status register in microcontroller?
The status register is a hardware register that contains information about the state of the processor. Individual bits are implicitly or explicitly read and/or written by the machine code instructions executing on the processor.
What is the standard form of PSW?
The Full form of PSW is Process Status Word, or PSW stands for Process Status Word, or the full name of given abbreviation is Process Status Word.
What is the use of PSW register in 8051?
The program status word (PSW) register is an 8-bit register, also known as flag register. It is of 8-bit wide but only 6-bit of it is used….8051 Flag Bits and PSW Register.
| CY | PSW.7 | Carry Flag |
|---|---|---|
| F0 | PSW.5 | Flag 0 available to user for general purpose. |
| RS1 | PSW.4 | Register Bank selector bit 1 |
How many registers are there in 8051?
The 8051 has 4 selectable banks of 8 addressable 8-bit registers, R0 to R7. This means that there are essentially 32 available general purpose registers, although only 8 (one bank) can be directly accessed at a time.
How many types of status registers are there?
The PSRs are subdivided into three status registers: Application Program Status register (APSR) Interrupt Program Status register (IPSR) Execution Program Status register (EPSR)
Which are different bits in program status register?
The Linux/ARM embedded platform ARM v6/v7 maintains a status register called the CPSR (current program status register) that holds four status bits, negative (N), zero (Z), carry (C), and overflow (O). These bits can be used for conditional execution of subsequent instructions.
What is the format of 8051 PSW?
The program status word (PSW) register is an 8-bit register, it is also referred to as the flag register the PSW register is 8-bit wide only 6-bit of it are used by the 8051, the two unused bits are user definable flags, four of the flags are called conditional flags, meaning that they indicate some conditions that …
What is program counter 8051?
The Program Counter (PC) is a 2-byte address which tells the 8051 where the next instruction to execute is found in memory. When the 8051 is initialized PC always starts at 0000h and is incremented each time an instruction is executed. It is important to note that PC isn’t always incremented by one.
What is the use of status register?
The status register lets an instruction take action contingent on the outcome of a previous instruction. Typically, flags in the status register are modified as effects of arithmetic and bit manipulation operations. For example, a Z bit may be set if the result of the operation is zero and cleared if it is nonzero.
What are registers in 8051?
Registers are used in the CPU to store information on temporarily basis which could be data to be processed, or an address pointing to the data which is to be fetched. In 8051, there is one data type is of 8-bits, from the MSB (most significant bit) D7 to the LSB (least significant bit) D0.
What is the flag register in the 8051 microcontroller?
The flag register in the 8051 is called the “Program Status Word [PSW]” register. The program status word [PSW] is an 8-bit register. Program status word is also referred to as the flag register. The PSW register is 8 bits wide, but only 6 bits of it are used by the 8051 microcontroller.
What is PSW register in microcontroller 8051?
The program status word [PSW] is an 8-bit register. Program status word is also referred to as the flag register. The PSW register is 8 bits wide, but only 6 bits of it are used by the 8051 microcontroller.
What are conditional flags in the 8051 PSW register?
The PSW register is 8 bits wide, but only 6 bits of it are used by the 8051 microcontroller. The remaining two unused bits are user-definable flags. From the 6 bits, the four of the flags are called conditional flags. These conditional flags indicate some conditions that resulted after an instruction was expected.
What is the difference between the 8051 and 251 variants?
The 8051 variants provide one special function register called PSW with this status information. The 251 provides two additional status flags, Z and N, that are available in a second special function register called PSW1. The following table describes the status bits in the PSW: