I am new to microcontroller programing and I have lost couple of chips due to Fuse settinsg while creating SPI interface in my microcontroller circuit. Yesterday I was watching a video from eev video blog where author was saying that he loves PIC chips due to the fact that no fuse settings in PIC would disable the ISP - SPI interface. So at any time you can program your chip in circuit. I know that these chips can be reset using parallel programmer. But this question came to my mind that I saw a PEN pin on Atmega128 which enables ISP-SPI programming. So if this pin is dedicated programming enable pin does this mean that no matter fuse settings are done it would not disable ISP-SPI for the Atmega128 ?
If not is there any microcontroller chip in Atmega where there no fuse bit would disable the in circuit programmer interface ?
Wouldnt a chip with permenent in circuit enabled a great boon for newbies ?