merger not working

[leo]

I need help! PIC16F877-20 does not oscillate at 20 MHz. I tried many chips and xtals. At 10 MHz they all oscillate.

At 10 Mhz ,however, there is no output:Midi in is present at input pins, but out pin is always at high level.(output is connected to a midi device).I should expect some kind of wrong timed midi signal, but level is always high.

I use for programming MPLAB ICD and the hex file provided by T.Klose.. Something maybe wrong in programming?(programming options,watchdog, memory 0000-1FFF, etc?).

Thanks,Leo

[TK.]

Hi Leo,

did you select the HS oscillator type?

Best Regards, Thorsten.

[leo]

GREAT! Very many thanks, it works ok.

I always used  for my programs 10 MHz xtals and XT option . I didn't notice the existence of HS option. For me XT meant xtal (any xtal !).

Now I am experimenting midi filter/processor. I do PIC programming, so I should easily achieve simple MIDI processing .

Bye, Leo.