HI, I am using P89v51rd2 to control L293D. My code is running on Eval board but not on the circuit I designed (all ports are reset to High state and code is not running). I used P0.0-P0.3 for input, P2.0-P2.3 as output. only other connection is 11.0592MHz xtal with 33pF caps. Please let me know what to do Regards, FD
does the 'loader' (esacademy or watever) reply 'OK'? wha t is your reset circuit?
and is that oscillating correctly?
Identify and correct any design and implementation issues?
I loaded the code using Flash magic on Evaluation board, Its running on evaluation board but when I remove the controller from board and put that on my board, it does not work
I don't know is it oscillating properly or not, should I check the oscillation with DSO? Is there any other way I can check oscillation?
Designing is just 4 inputs on port 0, 4 outputs at port 2 and on oscillating circuit with 11.0592 MHz and 33 pF capacitors. One Reset circuit with 0.1uF capacitor in parallel with switch and 8.2K resistor for Pull down at reset pin.
Well that would be a start, wouldn't it? The probe will alter the characteristics of the circuit, you could also try providing an external clock source.
Don't you think that is a pretty fundamental thing to know??!
I used to have a logic probe, but I'm not sure it would help determine frequency, just that the pin was toggling.
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Then again I used to test 9V batteries with my tongue.
Depends on what you mean by, "DSO": en.wikipedia.org/.../DSO
If you mean Digital Storage (or Sampling) Oscilloscope then, Yes - that would do it.
In fact, any oscilloscope - it doesn't need to be Digital or Storage (or Sampling)...