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Branching Group Instructions (Part-I) - Jump and Conditional jump

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JMP addr:
  • This instruction loads the program counter with the address given in the instruction.
  • Then the program execution continues from this location.
  • No flags are affected.
  • It is a three byte instruction.
  • Immediate addressing mode is used since the operand is given in the instruction itself.
Example:
JMP 5600H ; This instruction will load PC with 5600H and processor will fetch next instruction from 5600H.

JMP C240H ; This instruction will load PC with C240H and processor will fetch next instruction from C240H.

Jcond addr:
  • If the condition is true or satisfied, then this instruction causes a jump to an address given in the instruction.
  • If the condition is false or not satisfied, then this instruction just check and proceed further to execute the next instruction after it.
  • If condition is true, PC = addr and if condition is false, PC = PC + 3.
  • No flags are affected. Flags are only checked.
  • It is a three byte instruction.
  • Immediate addressing mode is used since the operand is given in the instruction itself.
NOTE: There is no jump on AC (Auxiliary Carry) flag.

Example:
JZ C200H ; This instruction will cause a jump to an address C200H and program counter will load  with C200H if Z = 1. But if Z = 0 then the next instruction will be executed.

JP 4320H ; This instruction will cause a jump to an address 4320H and program counter will load  with 4320H if S = 0. But if S = 1 then the next instruction will be executed.

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