Hello! Thank you Mr. Coppi for your help! I read the appnote-and will change my hardware now.I have read the max oscillator frequency is 16 MHz!? If that's right I have to configurate the internal frequency to 20MHz if I want to use the max. frequency that is possible??(I thouht I could use a 20MHz crystal?) How would you handle the Port0 configuration if there is still other hardware connected to this Port and occurs a wrong configuration? I ask because it seems that EA= high doesn't disable the external config. at my step.-In that case Port0 couldn't be used for other hardware,connected to this Port??! Best regards hannes
Hallo Hannes, we normally use a 4 MHz Xtal, with a x5 multiplication factor, thus running at 20 MHz internal. On your step (BA), you can still use P0 for whatever you want, but you must ensure that, while RSTIN is at 0 level, the configuration present on P0 is the correct one. You can just test it by simply keeping RSTIN low and then testing P0 bit by bit with a tester or an oscilloscope to read the configuration. Sorry, on BA step there is no way to change the configuration at run time; you must use a newer step if you want to use this feature. Ciao Bruno