Lpc2000

--- In lpc2100@yahoogroups.com, David Bermingham <crwpulsar@y...> wrote:
> Hi,
> Im looking for Help on the UART initialisation for the LPC, I need a
BAUD rate of 57600 bps but cant figure out the correct values to write
to the DLM/DLL registers...
>  
> A CCLK value of 60Mhz will give a default VPB(pclk) speed of
15MHz...Yes??
> The value in the DLM/DLL registers has to be 16 time the desired
baud rate, which gives 57600x16 = 921600. But this number is a 20 Bit
Integer....
>             .....11100001 00000000 0000.
>  
> Please can somebody explain where my calculations are going
wrong..or do I have to slow the processor down to get the required
Baud rate???
>  
> Thanks
> David

Hi David,
for serial baudrates just be "close enough". If you miss the target
baurate by less than 2.5% it is going to work! In order to hit the
57.6 kbaud, you van use a crystal running @ 14.7456 MHz. You will
reduce your performance by a stunning 1.7% :-) but for most
apllications this should not make a difference.
Cheers, Bob