Reply by Robert Adsett November 5, 20042004-11-05
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

" '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


An Engineer's Guide to the LPC2100 Series

Reply by shridhar joshi November 5, 20042004-11-05
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

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%6 ie LowBaudReg=0 HighBaudReg=1

hopes it will help you shridhar

--- 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 >
>

__________________________________


Reply by aravindar_manikandan November 5, 20042004-11-05

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