Lpc2000

Hi,
On LPC2103, Can I short VBat to V18?
The 2 pins are next to each other.
=> Simplify my PCB layout
=> Simplify my RTC backup circuit also, if V18 does not take too
   much current when power down. Single micropower 1.8V LDO used.

Vbat requires 3.3V for normal Operation. 
I do not fully understand the datasheet, does VBat work from 2.0V to
3.6V any time from chip operation to battery backup mode?
On PLCC44, It seems like VBat and V18 are bonded to same pin (read
from previous post) ??

I'm not using the full RTC section at the moment, may be will be 
just using the RTC's second tick interrupt as 1mS interval timer 
(Re-program prescaler to very fast "1 second").

Thanks