Self programming flash
Posted: Wed Jan 05, 2011 4:02 pm
Hello...
I have some kind of bootloader for AtTiny85 in mind and asking if someone have some experience with that.
My idea is:
Upload pages to upper part of memory,
after all pages are uploaded then I can disconect USB driver and jump to upper half of memory (where downloaded program is and has small copy routine at statr) and copy upper part of memory to the low part of memory.
The Problem I see is in uploading pages as Tiny is HALTED for aprox 5ms when page is writed. So within this 5ms the all jobs are in stall. How this will afect the VUSB? In doc's is that only few cycles the interrupt can be dissabled and this is a way longer.
of course in this way only 1/2 memory is available but 4k is still a lot.
Slavko.
I have some kind of bootloader for AtTiny85 in mind and asking if someone have some experience with that.
My idea is:
Upload pages to upper part of memory,
after all pages are uploaded then I can disconect USB driver and jump to upper half of memory (where downloaded program is and has small copy routine at statr) and copy upper part of memory to the low part of memory.
The Problem I see is in uploading pages as Tiny is HALTED for aprox 5ms when page is writed. So within this 5ms the all jobs are in stall. How this will afect the VUSB? In doc's is that only few cycles the interrupt can be dissabled and this is a way longer.
of course in this way only 1/2 memory is available but 4k is still a lot.
Slavko.