The 8085 is CISC
risc
risc
RISC
CISC
Pentium I processors are CISC.
CISC and RISC are the two categories that are used to classify CPU architecture. CISC is an acronym for complex instruction set computer.
The 8086/8088 is a CISC based architecture.
In CISC, the instruction set is very large that can be used for complex operations while in RISC the instruction set is reduced, and most of these instructions are very primitive. CISC computer's execution time is very high whereas RISC computer's execution time is very less. In, CISC code expansion is not a problem while in RISC code expansion may create a problem. In CISC, decoding of instructions is complex whereas, in RISC, the decoding of instructions is simple. CISC requires external memory for calculations, but RISC requires external memory for calculations. CISC has only a single register set while RISC has multiple register sets are present.
RISC stands for Reduced Instruction Set Computer. The design strategy of a RISC processor includes limiting the number of instructions. This does not mean that ALL RISC processors have less instructions than ALL CISC processors, but in general, they do.
CISC: Complex Instruction Set ComputerRISC: Reduced Instruction Set Computer
8051 is a CISC but having less number of instruction as comared to ARM which is RISC.CISC
There is still considerable controversy among experts about which architecture is better. Some say that RISC is cheaper and faster and therefor the architecture of the future.Others note that by making the hardware simpler, RISC puts a greater burden on the software. Software needs to become more complex. Software developers need to write more lines for the same tasks.Therefore they argue that RISC is not the architecture of the future, since conventional CISC chips are becoming faster and cheaper anyway.RISC has now existed more than 10 years and hasn't been able to kick CISC out of the market. If we forget about the embedded market and mainly look at the market for PC's, workstations and servers I guess a least 75% of the processors are based on the CISC architecture. Most of them the x86 standard (Intel, AMD, etc.), but even in the mainframe territory CISC is dominant via the IBM/390 chip. Looks like CISC is here to stay …Is RISC than really not better? The answer isn't quite that simple. RISC and CISC architectures are becoming more and more alike. Many of today's RISC chips support just as many instructions as yesterday's CISC chips. The PowerPC 601, for example, supports more instructions than the Pentium. Yet the 601 is considered a RISC chip, while the Pentium is definitely CISC. Further more today's CISC chips use many techniques formerly associated with RISC chips.So simply said: RISC and CISC are growing to each other.