What are the five different categories of 8051 instruction set?
What are the five different categories of 8051 instruction set?
Based on the operation they perform, all the instructions in the 8051 Microcontroller Instruction Set are divided into five groups….They are:
- Data Transfer Instructions.
- Arithmetic Instructions.
- Logical Instructions.
- Boolean or Bit Manipulation Instructions.
- Program Branching Instructions.
What is CPL in 8051?
Home » Instructions » CPL. The CPL instruction logically complements the value of the specified destination operand and stores the result back in the destination operand. Bits that previously contained a 1 will be changed to a 0 and bits that previously contained a 0 will be changed to a 1.
What is the purpose of PSW 3 and PSW 4 in 8051?
3 and PSW. 4 are designated as RSO and RSI, respectively, and are used to change the bank registers. They are explained in the next section.
What is PSW 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 DPH and DPL in 8051?
In 8051 assembly code, this address pointer is called DPTR. Because the 8051 is an 8-bit microcontroller, the 16-bit data pointer is controlled by two byte-wide registers, DPH (data pointer high-byte) and DPL (data pointer low-byte). The Triscend E5 CSoC device has two 16-bit data pointers, as shown in Figure 1.
What is JNC in ALP?
In 8085 Instruction set,we are having one mnemonic JNC a16, which stands for “Jump if Not Carry” and “a16”stands for any 16-bit address. This instruction is used to jump to the address a16 as provided in the instruction.
What is the difference between JC and JNC?
The program sequence is transferred to the memory address given in the operand based on the specified flag of the PSW….Difference between call and jump instructions in 8085 Microprocessor.
| Opcode | Description | Flag Status |
|---|---|---|
| JC | Jump on Carry | CY=1 |
| JNC | Jump on no Carry | CY=0 |
| JP | Jump on positive | S=0 |
| JM | Jump on minus | S=1 |
What is RAL in microprocessor?
In 8085 Instruction set, there is another mnemonic RAL,which stands or Rotate Accumulator Left and also involving Cy flag in rotation. It rotates the Accumulator contents to the left by 1-bit position.
What is the function of Cy PSW 7 flag in PSW?
CY, the carry flag − This carry flag is set (1) whenever there is a carry out from the D7 bit. It is affected after an 8-bit addition or subtraction operation….8051 Flag Bits and PSW Register.
| CY | PSW.7 | Carry Flag |
|---|---|---|
| AC | PSW.6 | Auxiliary Carry Flag |
| F0 | PSW.5 | Flag 0 available to user for general purpose. |
Why flag is also called PSW?
SECTION 2.6: 8051 FLAG BITS AND THE PSW REGISTER Like any other microprocessor, the 8051 has a flag register to indicate arithmetic conditions such as the carry bit. The flag register in the 8051 is called the program status word (PSW) register.
What does add R1 R2 R3 mean?
ADD: This instruction adds 2 values (from 2 registers or from a register and an immediate value) and puts them into a register. Similar format is used for SUB, MULT, DIV, MOD. For eg. “ADD R1 R2 R3;” will move the value R2+R3 into R1. “ADD R1 R2 #3;” will move the value R2 + 3 into R1.
