Dear,

That's why it is called a RISC (Reduced Instruction Set Computer). The RISC type of MCU has less instructions, but most, if not all instructions, are executed in less machine-cycles than the CISC counterpart. Therefore more code-lines do not necesarily mean longer execution time.

It's just a way of simplifying the architecture of your MCU by using the 20-80 rule: Throw out the 20% instructions that provoke the 80% of total complexity.


You should not interpret the above as advocacy for RISC or CISC. Both have their merrits.



rgds
Patrick