16F777 at 115200 baud

[BrianT]

I routinely run 115,200 on a PIC18F4620 at 20 MHz.
Works a treat. I always set char_pacing to 20 or more to give some more time for the receiving side to process the character.

HTH
BrianT

[HenrikOlsson]

The forumula they have in the maual is (1000000/baud)-20, which results in -11.

As Al pointed out (but didn't really spell out) the 1000000 comes from Fosc/4 and since you're running at 20MHz the formula becomes (5000000/115200) - 20 = 23. I don't know if 115200 "should" work at 20MHz but if you can't get it going try DEBUG instead.

/Henrik.

[cpayne]

Thanks for all the help. I understand fosc/4, but i am not sure Serout2 or serin2 uses that. I define the osc speed up top. I have to use 10000000 to get 19200 or 38400 to work with no issue. the debug may work for outgoing, but eventually i will need incoming... I am currently laying out another board with a 2 UART chip since hserin and hserout work fine at 115k and a 20mhz osc, but i would really prefer to use my existing chip.

-Charlie

[HenrikOlsson]

OK, you're probably correct then, sounds a bit strange though.... Anyway, if DEBUG does indeed work for the output then DEBUGIN will most likely work for the input - as long as you don't need to change pin or baudrate at runtime.

/Henrik.

[Charles Linquis]

Debug is much more "light weight", since the parameters are calculated at compile time, not every time the routine is called.

It works fast in both directions.