Microprocessor Design/Memory Unit
Microprocessors rely on memory for storing the instructions and the data used by software programs. The memory unit is responsible for communicating with the system memory.
Memory Unit
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Actions of the Memory Unit
[edit | edit source]All von Neumann CPUs store their instructions in memory.
In a Harvard architecture, the data memory unit and the instruction memory unit are two different units. However, in a Princeton architecture the two memory units are combined into a single module. Most modern PC computer systems are Princeton, not Harvard, so the memory unit must handle all instruction and data transactions. This can serve as a bottleneck in the design.
Timing Issues
[edit | edit source]The memory unit is typically one of the slowest components of a microcontroller, because the external interface with RAM is typically much slower than the speed of the processor.