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I am doing ADC interfacing using AT89S52 IC and i need 200ns delay for one of my control signals. if it is possible then can you please suggest me the assembly code to generate 200ns delay...
Andy posted:
Any instruction on any processor takes a finite length of time to execute.
He did not ask you to post your code; everybody here already understands what you want to achieve!
What you probably need to generate such a short delay is combine 2 facts: 1. Any instruction has an execution penalty. 2. You need an instruction that does not do anything at all but has a execution penalty.
Do you know what it is?
do u mean that it is nop...tell me what is the time delay it introduces..
Yes; nop is one way to generate a delay. How long that delay is depends on your chip - its clock settings and other factors (not being a C51 guy I cannot explain in detail; ARM7s have flash acceleration units etc. that also influence performance) and the efficiency of the code used. The best thing for you to do it to measure with a scope.
I am using AT89s52 Chip and the crystal i am using is 11.0592MHz and it have 2k onchip flash memory.so what may be the delay of nop instruction....is there any calculation to find the delay generated by nop using the data i have provided....
The Instruction Set Manual will include the timings for instructions.
For the 8051 architecture, this is chapter 2 of the so-called "bible" for the 8051 - links here: www.8052.com/.../120112
But be sure to check the specific documentation for your particular chip; many modern 8051 derivatives offer "accelerated" execution - ie, they consume less cycles to execute the instructions...
the pulse width given is 200ns
I seriously doubt that you'll be able to get a pulse on a GPIO pin shorter than 200ns with this microcontroller. In other words, no delay necessary.
minimum? maximum? or what?
Oh, come on. You don't need a crystal ball to answer that one, never mind the datasheet.
in another post today you refer to your post intended to make the OP go in a certain direction.
Do you REALLY doubt that Andy does not know the answer to his question ans is not "intended to make the OP go in a certain direction"
Erik
Er, what?
Yes, I REALLY doubt that Andy does not know the answer to his question. I also REALLY doubt that the OP does not know the answer to his question. Given that nobody REALLY doubts that they do not know the answer to the question perhaps it would be better to move on to something that somebody REALLY doubts that they know?
i really doubt that!
to do what get me accused of being too harsh:
to the OP READ THE DATASHEETS of your processor and ADC
to do what get me accused of being too harsh
Not at all. 'Read the manual' is excellent advice. I feel sure we've had this conversation before, possibly at some length.
Not at all is the opinion of some, "too harsh" is the opinion of others.
I could venture some guesses as to the identity of those of the opinion "too harsh", but I am sure they are fuming already and I do not want to add fuel to the fire.