Architechtural features

CISC:

• many instruction formats are possible;
• there are more addressing modes;
• makes use of multi-cycle instructions;
• instructions can be of a variable length;
• longer execution time for instructions;
• decoding of instructions is more complex;
• it is more difficult to make pipelining work;
• the design emphasis is on the hardware;
• uses the memory unit to allow complex instructions to be carried out.

RISC:

• uses fewer instruction formats/sets;
• uses fewer addressing modes;
• makes use of single-cycle instructions;
• instructions are of a fixed length;
• faster execution time for instructions;
• makes use of general multi-purpose registers;
• easier to make pipelining function correctly;
• the design emphasis is on the software;
• processor chips require fewer transistors.

Which architecture?

Compare the requirements of these two scenarios, and identify - with justifications, which hardware architecture would suit each scenario.

Consider the two following Scenarios:

Scenarios 1

A desktop computer used for video editing and gaming requires a powerful processor to handle demanding tasks like rendering complex graphics and processing large video files.

Requirements:

• High processing power: The processor needs to be able to perform a large number of calculations per second to handle the workload of video editing and gaming applications.
• Support for complex instructions: The processor should be able to execute complex instructions efficiently to reduce the number of instructions required for a given task.
• High instruction throughput: The processor should be able to execute multiple instructions simultaneously to minimize the overall processing time.

Scenario 2

A robotic arm used in a manufacturing plant requires a real-time microcontroller to control its precise movements. The microcontroller needs to be able to respond to sensor inputs and adjust the arm's position within very tight deadlines.

Requirements:

• Low power consumption: The robotic arm is battery-powered, so the microcontroller needs to be energy efficient to maximize its operating time.
• Predictable execution time: The micro-controller's responses must be predictable and consistent to ensure the arm's movements are accurate and safe.
• Small code size: The microcontroller has limited memory, so the code needs to be compact to fit within the available space.