Lpc2000

--- In lpc2000@yahoogroups.com, Robert Adsett <subscriptions@a...> wrote:
> At 07:15 PM 1/8/05 +0000, you wrote:
> >I'll take a look next week on the actual data quality being received
> >transmitted at the CPU. I agree with you, from the table in the user
> >manual for the LPC2106 you can run at 115200 at 12.288 MHz, so at
> >12MHz even though we'll probably have a small percentage error per
> >bit, we should still be OK.
> 
> I think one of us is reading the wrong line.  I see 12.288 MHz
topping out 
> at 38400.
> 
> What is missing is a description of what is limiting the match so
that it 
> could be determined for the actual crystal used.  I expect it's a
divisor 
> issue.
> 

I've had the UARTs on the LPC21xx LPC22xx running fine at 115.2k (e.g.
receiving large files with 32 bit CRCs). It just that the divisor
arrangement means the baud rate @ 12MHz is approx 1% out (with the PLL
multiplying the XTAL by 5 to 60MHz / VPBDIV = 1). I just wondered
whether the bootloader on the chip gives up if it can't get an exact
baud rate...

Jane


> If we knew what it was it should be straightforward to figure out which 
> baudrates will match (and maybe even switch crystals to meet
multiple neeeds).
> 
> Robert
> 
> 
> " 'Freedom' has no meaning of itself.  There are always restrictions,
> be they legal, genetic, or physical.  If you don't believe me, try to
> chew a radio signal. "
> 
>                          Kelvin Throop, III