| ??? 10/18/05 07:38 Read: times |
#102530 - Guaranteed parameters Responding to: ???'s previous message |
Erik Malund said:
we make a sign and announciator system for municipal buses that based on GPS announce next stop, change the signs, let the supervisor in his office see where the buses are, estimate time of arrival and display that at the shelters Ok, you don't make toys! ;-) I do not myself: I am a developing consultant, so I develop many different projects, but the most significant in last years is a robotic multi-axis autosampler for chemichal/biological analisys systems (gas-chromatography). Erik Malund said:
I disagree, the ONLY way to run multiple micros is with ONE clock source. If "this technique" refer to using XTAL2 you are right. We are saying the same thing. Erik Malund said:
This is often seen when one micro is used outside the guaranteed parametres. If upgraded to a newer chip or even the manufacturer change foundry everything fall apart. In your case I guess that since most often newer chips are faster (in risetime) that is what got you. Asd Kai stated it is next to impossible to measure oscillator output. I can not ensure it (I don't remember exactly, I should verify), but I think that in the old Intel and Philips 8051 family data sheets is specified that you can drive a XTAL1 using another XTAL2. It doesn't seem to be using a chip outside the guaranteed parameters. Erik Malund said:
BTW, also using TF2 to generate a software interrupt is not exactly the right way to use it... I know. why not, I have done it many times. As you said, "this is often seen when one micro is used outside the guaranteed parametres. If upgraded to a newer chip or even the manufacturer change foundry everything fall apart." No one guarantees that software setting an int. flag causes the interrupt to be called, in the datasheets. Fausto |
