AVR Microcontroller Data Transfer Instructions: Efficient Data Movement
Learn about data transfer instructions in AVR microcontrollers, focusing on their role in moving data between registers and memory. This guide covers various instructions, including MOV, LD, and ST, and provides examples for efficient data manipulation in AVR programming.
Data Transfer Instructions in AVR Microcontrollers
Data Transfer Instructions: An Overview
Data transfer instructions move data within an AVR microcontroller. They're fundamental for copying data between registers and memory locations. These instructions are also known as copy instructions. The AVR architecture provides a variety of instructions for efficient data movement.
Types of Data Transfer Instructions
AVR microcontrollers support various data transfer operations:
1. Register to Register
Copies data from one register to another.
Example: Move data from register B to register A:
MOV A, B
2. Register to Memory
Copies data from a register to a specific memory location.
Example: Store data from accumulator A to memory location 201k:
STA 201k
3. Memory to Register
Loads data from a specific memory location into a register.
Example: Load data from memory location 2020k into accumulator A:
LDA 2020k
4. Constant to Register (Immediate Loading)
Loads a constant value directly into a register.
Example: Load the constant value 05 into accumulator A:
MVI A, 05
AVR Data Transfer Instructions: Detailed Overview
| Instruction | Mnemonic | Description | Syntax |
|---|---|---|---|
| Move Register | MOV | Copies data from one register to another | D = S |
| Load Direct from Data Space | LDS | Loads a byte from data space into a register | D = Value at K |
| Load Indirect from Data Space | LD | Indirectly loads data from memory (address in register S) to register D | D = Value at memory location stored in S |
| Load Immediate | LDI | Loads a constant into a register | D = K |
| Load Program Memory | LPM | Loads a byte from program memory (address in Z register) into register D | D = Z |
| Input from I/O Location | IN | Loads data from I/O space into register D | D = I/O(A) |
| Output to I/O Location | OUT | Stores data from register D to I/O space | I/O(A) = D |
| Store Direct to Data Space | STS | Stores a byte from a register (S) to a data space location (K) | K = S |
| Store Indirect From Register to Data Space | ST | Indirectly stores data from register S to memory (address in register D) | Memory location stored in D = S |
| Push Register onto Stack | PUSH | Pushes a register's contents onto the stack | STACK = D |
| Pop Register from Stack | POP | Pops a byte from the stack into a register | D = STACK |
Conclusion
Data transfer instructions are fundamental to AVR microcontroller programming, enabling efficient data manipulation between registers and memory. Understanding the nuances of each instruction is key to writing effective code.