Gil Simon wrote:
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Hi,

Ok I get it.

1. EPROM faster than micro, no effect on program speed.

2. EPROM slower than micro, it won't work.


Easy sounding words, but Gil, how you think, this can be decided in practice ???

Yes Steve, so it seems a good topic for the tutorial 1

And Gil, I see no joke on it.


Have you already read the data sheets of all needed devices (EPROM, 573 latch, 8051 derivate) and done the worst case calculation ?

Please watch, the calculation must be done with exact the same devices which you want to use (same manufacturer, number, revision) !
Not any other EPROM or 8051 derivate.

So the worst case calculation was a 2 step task:
At first decide, which maximal access time the EPROM should have. Then search a device and select the needed speed class.
Then get the data sheet of exact this device and verify the calculation again, if it really fits.
The realibility fanatics (military or medical applications) use then the next faster speed class to get an additional safety distance.


Also in most cases it crashes not completely, if you break this important rule. At first it reduce the reliability (higher noise, temperature, voltage, pcb, load, ... sensitivity) !
Since it increase the risk to do a single wrong code fetch. And anybody know, what this mean.


Peter