What are flags in microcontroller?
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What are flags in microcontroller?
Flags are a modified kind of register that record the condition of a microprocessor’s calculation. For instance, a “zero status” flag is activated only when the microprocessor’s calculation concludes with a “zero” status.
What is flag register in microcontroller?
The Flag register is a Special Purpose Register. Depending upon the value of result after any arithmetic and logical operation the flag bits become set (1) or reset (0). In 8085 microprocessor, flag register consists of 8 bits and only 5 of them are useful.
Which flag is absent in 8051?
Zero flag is present in 8085 but not in the 8051.
Which register contains all the flags of 8051?
Internal RAM of 8051 is 128 bytes out of which 32 bytes are stored in registers( 8085, 8086 has 7,8 registers only ). These all 32 registers are divided into 4 banks, each bank has 8 registers starting from R0 to R7….Flag register of 8051 microcontroller.
| RS1 | RS0 | Bank |
|---|---|---|
| 1 | 1 | Bank 3 |
What is Flag use?
Flags originally were used mainly in warfare, and to some extent they have remained insignia of leadership, serving for the identification of friend or foe and as rallying points. They are now also extensively employed for signaling, for decoration, and for display.
What do flags mean?
Depending on where they fly, flags can represent freedom or control, danger or safety. In the context of modern times, flags are best known as national symbols — and they’re used to air a country’s past, present, and future vision all rolled into one.
What are flags in 8051?
8051 Flag Bits and PSW Register Four of the flags are called conditional flags, which means that they indicate a condition which results after an instruction is executed. These four are CY (Carry), AC (auxiliary carry), P (parity), and OV (overflow). The bits RS0 and RS1 are used to change the bank registers.
How many types of flag registers are there?
6 flag registers
(a) Status Flags – There are 6 flag registers in 8086 microprocessor which become set(1) or reset(0) depending upon condition after either 8-bit or 16-bit operation.
Why flag is also called PSW?
The program status word (PSW) register is an 8-bit register. It is also referred to as the flag register. The two unused bits are user-definable flags. Four of the flags are called conditional flags, meaning that they indicate some conditions that result after an instruction is executed.
What do you mean by flag register?
The FLAGS register is the status register that contains the current state of a CPU. The size and meanings of the flag bits are architecture dependent.
What is flag Code?
In programming, a flag is a predefined bit or bit sequence that holds a binary value. Typically, a program uses a flag to remember something or to leave a sign for another program.