ADUC842/843 BAUD RATE & SUPPLY

ADUC842/843 are single clock devices.
Given that timers on a standard 8052 are increment by 1 with each machine
cycle, but on the ADuC841/ADuC842/ADuC843, one machine cycle is equal to one
clock cycle means therefore the timers are increment at the same rate as the
core clock.
So, with a crystal of 29.4912 MHz, SMOD as 0 and TH1 reload as 0xFE the baudrate
for mode 1 as 8-Bit UART with variable baud rate, equals to 460800 as desired.
This document describes everything in detail.
www.analog.com/.../ADUC841_842_843.pdf

The ADuC841 and ADuC842 are identical with the exception of
the clock oscillator circuit. The ADuC841 is clocked directly
from an external crystal up to 20 MHz whereas the ADuC842
uses a 32 kHz crystal with an on-chip PLL generating a
programmable core clock up to 16.78 MHz

With these frame in mind there is the option to use Timer 3 Generated Baud Rates.
Using the internal 32768Hz clock crystal PLL locked x512 gives Fcore as 16.777216MHz
Setting up the appropriate T3 for baud rate generator with

DIV = 1 (rounded down)
T3FD = 9 (nearest integer)

the achieved baud rate is 459649 bits per second,
as of -0.25% deviation error from the desired 460800.

Thnx a lot for the solution.

Earlier even i had thought to use timer 3 in the same way.

But after going through the below mentioned site
ics.nxp.com/.../

I realized that the maximum baud rate in timer mode in my case is 16777216/64 = 262144 baud rate.

The baud rate which i want to achieve is 460800 which is obviously larger than 262144.

pls give me some alternate solution

Regards,
Mayuri

How to you compare an Analog Devices microcontroller as ADuC842/843
with NXP microcontrollers for uart setup?
Please check the formentioned datasheet of ADuC842/843 about Timer3 as baud rate generator.

yeah i got it...

thnx a lot for the help
:)

regards,
Mayuri