can any one tell me 8085 is pipe lined processor or not?
i think it's not? but my friends are telling me that there are differnt fetch and execution cycle.
You are right. It is not. See the datasheet and you will realize that the machine cycles are sequential, i.e. they occur one at a time and there is no different machine cycles executing at same time.
Hi, But is it really a pipeline in the sence that it is executing ONE instruction at a clock ??.. if not then its a normal state machine part of von neumann.
A true pipelined cpu is taking an instruction at clock one and the next at clock two, but what you mean is that it takes an instruction and devices it into parts. This is also done by the 8051 .....
Pipelining is when we break combinational path by adding reg. in between. When we were kids at that time we were told 8086 is pipelined as it has instruction que..... however that is not pipelineing in true sense , another thing is each stage of pipelining always add one clock latancy, this can easily tell you if the given design is pipelined, and upto what extent ...
8085 is not purely pipelined processor!
But for single byte instructions it does pipelining,
while executing currently fetched and decoded instuction
it fetches next instruction to be executed. It you try to write
verilog code for 8085 you will get this concept. Or you can check
gl85 vhdl code for 8085! I have implemented my verilog 8085 in same way!
I think 8085 is semi-pipeline through the Instruction Register (according to its architechture) and it is true that 8086 has 6 que while 8088 has 4 These microprocessors are the real piped-line ones.
These processors are NOT pipelined, maybe your VHDL code you have has build a core that is pipelined and able to run 8085/86 code but the original is NOT pipelined. If you know the PIC microchip fam, they also have a que of 2 instructions and still is NOT pipelined.