On Tue, 2007-05-29 at 17:53 -0600, Phillip Coiner wrote:
>  
> Hi all
> 
> I am using a 18F6620 to talk to a GPS receiver over a serial port that
> speaks NMEA (the default rate for NMEA is 4800 baud).
> 
> No problemo all is fine and working well but now I want to use a
> new/different GPS receiver that has a default serial speed of 115200 baud.
> 
> I tell my compatriots that I might have to clock the device faster (BTW
> current PIC clock rate is 4MHz) to do 115200 but it should be no problem to
> run the device at a higher baud rate.
> 
> So I dig out the section of the data sheet for the baud rate generator but
> much to my chagrin I don't see 115200 any where on the sheet..even at the
> higher clock rates???????
> 
> 
> I do see some rates that are close to 115200 there is what appears to be 96K
> but the real rate would be 104.17K and (what heck is this about ???) is this
> the close enough for hand grenades setting?
> 
> I find it a little hard to believe that a part that can be clocked at 40MHz
> doesn't support anything higher that 19.2 in this day and age when most
> serial parts support 115.2k (well there is 76.8k on the data sheet but I've
> never seen anything that used that rate).
> 
> Is it possible to do 115200 with my device or am I SOL with this part?

The data sheet simply lists some "common" baud rates as examples in the
tables. Using the formulas given in the datasheet you can manual derive
the settings necessary to get pretty much any baud rate you'd like.

TTYL

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