Von Neumann and Harvard architecture both are computer architectures. They describes a design architecture for an electronic digital computer .
| Harvard Architecture | Von Neumann Architecture |
|---|---|
| Harvard architecture has physically separate pathways for instructions and data. | Von Neumann architecture uses same physical pathways for instructions and data . |
| It has one dedicated set of address and data bus for reading data from and writing data to memory, and another set of address and data buses for fetching instructions. | It has same set of data and address buses for memory read/write and fetching instructions. |
| Under harvard architecture the CPU can both read an instruction and perform a data memory access at the same time . | Under pure von Neumann architecture the CPU can be either reading an instruction or reading/writing data from/to the memory. Both cannot occur at the same time since the instructions and data use the same bus system. |
| Harvard architecture machine has distinct code and data address spaces: instruction address zero is not the same as data address zero. | Von Neumann architecture has same data address and instruction address . |