SWAP INSTRUCTION ||Microcontroller ||

SWAP Instruction in Microcontrollers The SWAP instruction is a fundamental operation in microcontroller programming. It is used to exchange the positions of nibbles (4-bit segments) within a byte. This operation can be particularly useful in various low-level data manipulation tasks. Description: The SWAP instruction typically operates on a single 8-bit register, where it exchanges the higher-order nibble (the upper 4 bits) with the lower-order nibble (the lower 4 bits). This can be visualized as follows: Before SWAP: Register value: 0xAB (in hexadecimal), where A represents the higher-order nibble and B represents the lower-order nibble. After SWAP: Register value: 0xBA. In binary, this operation looks like: Before SWAP: Register value: 1010 1011. After SWAP: Register value: 1011 1010. How It Works: The microcontroller fetches the value from the specified register. It splits the byte into two nibbles. It exchanges the positions of these nibbles. The modified byte is stored back into the same register. Usage Example: Consider a microcontroller register named R1 with an initial value of 0x3C (0011 1100 in binary). Initial state: R1 = 0x3C (binary: 0011 1100) After executing SWAP instruction: R1 = 0xC3 (binary: 1100 0011)