DEP 5

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DEP 5 Revision Notes

-RISC AND CISC

-RISC CPUs run at a lower clock speed than CISC CPUs. They can perform simpler tasks more quickly than CISC, but more intensive tasks will be better on a CISC CPU.

-Most computers and laptop use CISC and smartphones and tablets use RISC.

- RISC CPUs use fewer instructions than CISC. CISC generally have hundreds of instructions in comparison to RISC that usually has a lot less.

-To do complex tasks, RISC CPUs must combine simple operations from their reduced instruction set.

-CISC CPUs are physically larger because of all the instructions they use.

-CISC CPUs are bigger than RISC CPUs, they use more electricity. RISC CPUs are designed to use less power and they can go into sleep mode when not actively processing a program.

-LMC

-A Little Man Computer (LMC) is a simulator which has many of the basic features of a computer. The LMC uses the Von Neumann architecture.

-There are 100 memory addresses in the computer memory are numbered 0 to 99.

-LMC uses machine code.

-Each assembly language instruction is made up of 3 letters, usually followed by the memory address of the data the CPU is to act on.