Lpc2000

hi,

i am using 14.746Mhz crystal for lpc210x.i want to find baudrate 
setting for this crytal frequency.anybody explain with the formula

rgds,
mani

hi 
here is the uart baud rate calculation

Baudrate=(ProcessorClock)/(16*BaudDivider Reg)

 if you are using 14.7456MHz crystal and not using
Internal  PLL of the lpc   and processor clock is div
4 
HERE IS THE FORMULA

BAUDRATE=(14.7546MHz/4)/(16*(BaudDivider Reg))
i.e for 14400 Baudrate
14.7456MHz/(4*16*16)
BaudDivider Reg=16

if you are using PLL say it is 4 times the Crystal
Frequency

BAUDRATE=(14.7546MHz*4)/(16*(BaudDivider Reg))
i.e for 14400 Baudrate
14.7456MHz*4/(16*256)
BaudDivider Reg=256 ie LowBaudReg=0 HighBaudReg=1

hopes it will help you 


shridhar

--- aravindar_manikandan
<aravindar_manikandan@...> wrote:

> 
> hi,
> 
> i am using 14.746Mhz crystal for lpc210x.i want to
> find baudrate 
> setting for this crytal frequency.anybody explain
> with the formula
> 
> rgds,
> mani
> 
> 
> 
> 



		
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At 06:14 PM 11/5/04 +0000, you wrote:
>i am using 14.746Mhz crystal for lpc210x.i want to find baudrate
>setting for this crytal frequency.anybody explain with the formula

Well it will depend on the pll and vpb settings as well as the crystal speed.

Basically

  divisor = vpbrate/(baud *16);

  U0DLM = high 8 bits of divisor
  U0DLL = low 8 bits of divisor

There is a generalized version in the uart driver in the lpc-newlib .

Robert

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