Video image generator superimposition for analog PAL signals, with Atmega328, for your retro OSD titles
https://retrofficina.glgprograms.it/
giomba
d91201dcfd
actually this does not work, because polling requires:
in
andi
brne
which takes 4 clock cycles, that, on average, means a 2 clock offset,
while interrupts occur during a rjmp, which takes 2 clocks, which means,
on average, only 1 clock cycle of offset
I am not interested in higher or lower overhead: I am just interested in
minimizing its variance.
Being late of a few clock cycles, is not a problem: it just means that
the picture will be slightly shifted toward the right border; but,
starting the picture 1 or 2 clock cycles before (on one line), and 1 or
2 clock cycles after, on another line, means that it just wiggles sligthly
left and right
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| .gitignore | ||
| Makefile | ||
| const.h | ||
| macro.h | ||
| main.S | ||
| main.c | ||