Harvard architecture is a computer system design where the instruction memory (program memory) and data memory (data storage) are physically separated from each other. This separation makes it easier for the processor to access both program instructions and data simultaneously. The two memories can also be accessed at different speeds, which allows for faster operation compared to other architectures such as Von Neumann or CISC-based architectures. This type of architecture has been around since the mid-1960s, when it was first used in an IBM mainframe computer.   A Harvard architecture microcontroller contains two separate memories – one for instructions and one for data which are both connected to an arithmetic logic unit or ALU. The instructions tell the processor what tasks to perform on the data stored in memory, while the data stores numerical values that can be manipulated by the processor.   The ALU performs mathematical operations on those values, such as addition, subtraction, multiplication, and division and logical operations like AND/OR/NOT gates. It also receives inputs from external devices, such as sensors or switches, that can affect how it operates on its data sets. Finally, it produces outputs that can control external devices such as motors or displays.   The advantage of having two separate memories is that multiple operations can be performed in parallel, making them much faster than traditional single-memory architectures like Von Neumann's model or RISC-based systems. Additionally, since there's no need to move data between memories before performing calculations, they're also more power efficient than their counterparts.