Found 558 Articles for Microprocessor

In 8085 Instruction set, CPO is a mnemonic, which stands for “Call if Parity Odd”. This instruction is a used to branch to the subroutine whose 16-bit address is provided in the instructions, only if P flag value is 0. If Z flag value is 1, program flow continues in the main program sequentially. It is a 3-Byte instruction.Mnemonics, OperandOpcode(in HEX)BytesCPO LabelE43Let us consider the following sample code for a better explanation –AddressHex CodesMnemonicComment200031LXI SP, 5000HSP ← 5000H.Initializing the SP200100Low order Byte of the address200250High order Byte of the address20033EMVI A, 40HA ← 40H, Initializing the Accumulator with initial value ... Read More

In 8085 Instruction set, CZ is a mnemonic, which stands for “Call if Zero”. This instruction is used to branch to the subroutine whose 16-bit address is provided in the instruction, only if the Z flag value is 1. If Z flag value is 0, program flow continues in the main program sequentially. It is a 3-Byte instruction.Mnemonics, OperandOpcode(in HEX)BytesCZ LabelCC3Let us consider the following sample code for a better explanation –AddressHex CodesMnemonicComment200031LXI SP, 5000HSP ← 5000H.Initializing the SP200100Low order Byte of the address200250High order Byte of the address20033EMVI A, 40HA ← 40H, Initializing the Accumulator with initial value 40H20044040H ... Read More

In 8085 Instruction set, CNZ is a mnemonic, which stands for “Call if Not Zero”. This instruction is used to branch to the subroutine whose 16-bit address is provided in the instruction, only if the Z flag value is 0. If Z flag value is 1, program flow continues in the main program sequentially. It is a 3-Byte instruction.Mnemonics, OperandOpcode(in HEX)BytesCNZ LabelC43Let us consider the following sample code for a better explanation –AddressHex CodesMnemonicComment200031LXI SP, 5000HSP ← 5000H.Initializing the SP200100Low order Byte of the address200250High order Byte of the address20033EMVI A, 40HA ← 40H, Initializing the Accumulator with initial value ... Read More

In 8085 Instruction set, CC is a mnemonic, which stands for “Call if Carry”. This instruction is used to branch to the subroutine whose 16-bit address is provided in the instruction, only if Cy flag value is 1. If Cy flag value is 0, program flow continues in the main program sequentially. It is a3-Byte instruction.Mnemonics, OperadOpcode(in HEX)BytesCC LabelDC3Let us consider the following sample code for a better explanation –AddressHex CodesMnemonicComment200031LXI SP, 5000HSP ← 5000H.Initializing the SP200100Low order Byte of the address200250High order Byte of the address20033EMVI A, 40HA ← 40H, Initializing the Accumulator with initial value 40H20044040H as operand200506MVI ... Read More

In 8085 Instruction set, CNC is a mnemonic, which stands for “Call if Not Carry”. This instruction is used to branch to the subroutine whose 16-bit address is provided in the instruction, only if Cy flag value is 0. If Cy flag value is 1, program flow continues in the main program sequentially. It is a3-Byte instruction.Mnemonics, OperandOpcode(in HEX)BytesCNC LabelD43Let us consider the following sample code for a better explanation –AddressHex CodesMnemonicComment200031LXI SP, 5000HSP ← 5000H.Initializing the SP200100Low order Byte of the address200250High order Byte of the address20033EMVI A, 40HA ← 40H, Initializing the Accumulator with initial value 40H20044040H as ... Read More

In 8085 Instruction set, depending upon one of the flag bit values (excluding AC flag bit), the conditional call instructions will branch to a subroutine. The branch takes place based on the value of Cy flag, Z flag, P flag, or S flag. There is no call instruction based on the value of AC(Auxiliary Carry) flag bit. This is because generally, no one is interested in branching to a subroutine based on this flag bit value. The conditional call instructions are 3 Bytes in length, 1 Byte for the opcode, and another 2 Bytes for the subroutine address i.e.low-order Byte ... Read More

Sometimes in 8085assembly language coding, we require to repeat a certain program segment for multiple times. In those situations, we can define sub-routines. In those subroutines, we can enclose our repeatedly reusable Instruction set or code. And then as when required we shall call those sub-routines accordingly. Sub-routines can also be called as procedures.Whenever the instructions in a subroutine are required to be executed, we branch program control to the subroutine using th CALL instruction.  CALL is a 3-Byte instruction, with 1 Byte for the opcode, and 2 Bytes for the address of the subroutine. CALL mnemonics stands for “call ... Read More

In 8085 Instruction set, we are having one mnemonic JM a16, which stands for “Jump if Minus” and “a16” stands for any 16-bit address. This instruction is used to jump to the address a16 as provided in the instruction. But as it is a conditional jump so it will happen if and only if the present sign flag value is 1. If the sign flag value is 0, program flow continues sequentially. It is a3-Byte instruction.Mnemonics, OperandOpcode(in HEX)BytesJM LabelFA3Let us consider one example of this instruction type JM 4000H. It is a 3-Byte instruction. The result of the execution of ... Read More

In 8085 Instruction set, we are having one mnemonic JP a16, which stands for “Jump if Positive” and “a16” stands for any 16-bit address. This instruction is used to jump to the address a16 as provided in the instruction. But as it is a conditional jump so it will happen if and only if the present sign flag value is 0. If the sign flag value is 1, program flow continues sequentially. It is a3-Byte instruction.Mnemonics, OperandOpcode(in HEX)BytesJPLabelF23Let us consider one example of this instruction type JP 4000H. It is a 3-Byte instruction. The result of execution of this instruction ... Read More

In 8085 Instruction set, we are having one mnemonic JPE a16,  which stands for “Jump if Parity Even” and “a16” stands for any 16-bit address. This instruction is used to jump to the address a16 as provided in the instruction. But as it is a conditional jump so it will happen if and only if the present parity flag value is 1. If the parity flag value is 0, program flow continues sequentially. It is a 3-Byte instruction.Mnemonics, OperandOpcode(in HEX)BytesJPE LabelEA3Let us consider one example of this instruction type JPE 4000H. It is a 3-Byte instruction. The result of execution ... Read More