Lpc2000

Hi,
see some comments below.
> 
> If you are going to add a 32 kHz crystal input for the RTC, it would
> be very useful to make the RTC power independant of the rest of the
> chip.  The Atmel AT91M55800A did this very well.  The RTC can be used
> to control the power to the rest of the chip for timer based power
> savings.  The RTC runs on a separate Vdd and can be powered by a Li
> coin cell for years.  

We need to combine power down with running the RTC -> no separate Vdd
for the RTC.

> 
> I would also suggest that the PLL be designed so that the 32 kHz clock
> can be the reference for the master clock PLL to save the need for a
> second crystal or oscillator.  
> 
> These suggestions can save around $2 in system cost in a small
> embedded system which is what your parts are targeted to.  
> 
A PLL that is as well accurate (low jitter) as low power while it
multiplies by factors >1000 does, to my best knowledge, not exist.
Having CAN as one of our standard interfaces, we need to support
"even" frequencies such as 16 MHz, 24,48,60 which can all be used to
get the standard CAN baudrate while still providing good enough
baudrates for UARTs. Unfortunately 32768 Hz is not a good base
frequency for any serial communication that needs standard transmition
rates. The second (32kHz) oscillator is optional for those who want to
use the RTC during Power Down. I am curious how many applications will
actually be using this feature. 

> BTW, if you go to a single power voltage approach, which voltage will
> it be, 3.3 or 1.8?  I don't understand how you can run the core from
> 3.3 volts and I don't understand how you can have 5 volt tolerant IO
> (or 3.3 for that matter) with 1.8 volt powered IOs.  You're not
> putting an LDO inside the chip are you?  That's one of the features
> they use on the newest CPLDs that ruin their quiescent power ratings.

It is going to be 3.3V.  Hint: low power DC-DC internal

Another fact: in processes 0.18 um and smaller it will be very close
to impossible to get quiescent current in the range of 1 uA.
Want to know more, find some articles about deep submicron processes
and leakage.

Regards, Robert