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
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.