With PIN register probably faster. One instruction for the register, one branch to jump back to the previous instruction, probably worth checking how fast this runs
while(true) PIND = 0b10000 ; // toggle D4
With PIN register probably faster. One instruction for the register, one branch to jump back to the previous instruction, probably worth checking how fast this runs
while(true) PIND = 0b10000 ; // toggle D4