[avr-libc-dev] _delay_us() - Documentation for maximum possible delay

[Boyapati, Anitha]

http://www.nongnu.org/avr-libc/user-manual/group__util__delay.html

The above link says, the maximal possible delay for _delay_us() is 768 us / 
F_CPU in MHz. However, as per the below computation, it should be 765us.
(Max value of _ticks when it is of uint8_t type is 255.)

_ticks = (F_CPU /3e^6)* _us

=> _us = 765/F_CPU in MHz


Also, any reason why _ticks is chosen to be uint8_t type (but not uint16_t or 
uint32_t)?



Thanks
Anitha