Questions and answers

What are the differences between LJMP and SJMP instructions?

What are the differences between LJMP and SJMP instructions?

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SJMP LJMP AJMP
It uses 8 bit address. It uses 16 bit address It uses an 11 bit address
2 byte instruction. 3 byte instruction 2 byte instruction
Conditional branch instruction can use,relative JMP. Cannot use long JMP Cannot the JMP absolute
Address calculation PC is equal to 11 bit PC is equal to 16 bit.

What is LJMP instruction?

The LJMP instruction transfers program execution to the specified 16-bit address. The PC is loaded with the high-order and low-order bytes of the address from the second and third bytes of this instruction respectively. No flags are affected by this instruction.

What is the size of SJMP instruction?

Branching range Instruction length
AJMP (Absolute jump) Within the 2 K page. 2 bytes
LJMP (Long jump) Anywhere in the 64K code space 3 bytes
SJMP (Short jump) Anywhere in the 256 code space 2 bytes

What is SJMP microcontroller?

Home » Instructions » SJMP. The SJMP instruction transfers execution to the specified address. The address is calculated by adding the signed relative offset in the second byte of the instruction to the address of the following instruction.

What is size of Long jump LJMP instruction of 8051?

LJMP is an unconditional long jump. It is a 3-byte instruction in which the first byte is the opcode, and the second and third bytes represent the 16-bit address of the target location. The 2-byte target address allows a jump to any memory location from 0000 to FFFFH.

What is the difference between short jump and long jump instruction?

I’ve read that short jumps are to be used when the relative jump is less than 124 in address, and long jumps should be used otherwise.

What is the size of LJMP instruction in 8051?

What does CMP do in assembly?

The CMP instruction compares two operands. It is generally used in conditional execution. This instruction basically subtracts one operand from the other for comparing whether the operands are equal or not.

What are the different types of instruction set of 8051?

They are:

  • Data Transfer Instructions.
  • Arithmetic Instructions.
  • Logical Instructions.
  • Boolean or Bit Manipulation Instructions.
  • Program Branching Instructions.

What does SJMP mean?

SJMP

Acronym Definition
SJMP St. James Music Press (est. 1992; Tryon, NC)
SJMP St. Joseph Morrow Park High School

What is full form of SJMP?

SJMP. St Joseph’s Morrow Park. Community » Parks & Recreation.

What are the unconditional jump instructions in 8051?

In the 8051 there are two unconditional jumps: LJMP (long jump) and SJMP (short jump). Each is discussed below. LJMP is an unconditional long jump. It is a 3-byte instruction in which the first byte is the opcode, and the second and third bytes represent the 16-bit address of the target location.

What’s the difference between SJMP and LJMP?

LJMP: we could not live with it. Universal jump. SJMP: shorter version to save code space. AJMP: not sure, can save some code space if the compiler can replace LJMPs withing 2K block with AJMPs. With 2K devices this is easy and saves some code space.

What is the difference between sjump and ljump in a microcontroller?

It uses 16 bit address,3 byte instruction. PC is equal to 11 bit. sjump means means it is short jump it will be every time jump in 8 bits and ljump means long jump it will be jump to 16 bits . Which is the best microcontroller?

How is the address of The SJMP instruction calculated?

SJMP. The SJMP instruction transfers execution to the specified address. The address is calculated by adding the signed relative offset in the second byte of the instruction to the address of the following instruction. The range of destination addresses is from 128 before the next instruction to 127 bytes after the next instruction.

How big is the long pointer in LJMP?

ljmp ImmPtr or *mem48 use a four- or six-byte operand as a long pointer to the destination. In Real Address Mode or Virtual 8086 mode, the long pointer provides 16 bits for the CS register and 16 or 32 bits for the EIP register.