bootloader questions

[mischl]

hi steve

thans a lot for your answers.

the circuit is at 5volt so no problems with brown out.

a question to the oscillator selection : i burned the 4mhz bootloader with HS set as config fuse. as i read in the datasheet, there is a table with testing at 4mhz of both, hs and xt. is this correct to use hs at 4mhz?

thanks again

[mister_e]

Usually XT is for 4MHZ. I heard some lazy crystal (not resonator) may work better with HS but... there's certainely something better to do prior using HS fuse... well... as now i never have any problem with any 4MHZ crystal i use, and always set XT fuse for that. So is this because of the HS fuse? Maybe yes maybe no. It's sounds to me a bad crytsal or PIC start-up for sure but why? Bad capacitor, bad crystal, HS fuse. The only thing i can suggest is to set to XT and test it. Same problem? Could also be caused by a slow start-up power supply... Power-up timer fuse 'may' help.