The Hack computer is a 16-bit non-Neumann machine, it consists of a CPU, separate memory modules for instructions and data, a screen, and a keyboard. Most general-purpose computers do not partition the address space for data and instructions. It is not possible to feed the instructions and data at the same time in general-purpose computers because the instructions and data need to go in the same space. To overcome the problem most general-purpose computers, utilize two-cycle work: the fetch cycle and the execute cycle.
The Hack Architecture is different from general-purpose computers because it partitions the address space and it allows a single cycle fetch-execute logic. The problem with hack architecture, the programs cannot be changed easily because the instructions are stored in read-only memory (ROM).
Difference between RISC and CISC
The term RISC stands for “Reduced Instruction Set Computer” and CISC stands for “Complex Instructions Set Computer”.
1. CISC has a memory unit that helps in the implementation of complex instructions, but RISC lacks the memory unit.
2. CISC enables microprogramming units, while RISC uses hard-wired programming.
3. In comparison to RISC, CISC is an easy compiler design.
4. In terms of calculation speed, RISC beats the CISC because RISC has faster and more precise calculations.
5. The decoding of instructions is simple in RISC in comparison to CISC.
6. RISC leaves CISC behind in execution time.
7. CISC needs an external memory for calculation but RISC doesn’t need one.
Advantages and disadvantages
Since the calculation time is less in RISC, it is ideal for use in high-end applications like video processing, telecommunications, and image processing. RISC speed operation can be maximized, and the execution time can be minimized. The efficiency of the RISC processor depends on the programmer’s knowledge or the compiler. While changing the CISC code to RISC code if the programmer poorly makes the changes then there will be a lack of efficiency in the RISC processor. The advantage of CISC architecture is, microprogramming is an easy assembly language to implement and less expensive than hard-wiring the control unit. Micro coding new instructions helps the designer to make CISC upgrade compatible. The performance of the machine is slow. The performance is slow due to the amount of clock time taken by different instructions.