Lpc2000

I'm using the lpc2138:

Q. How do you read the clock registers without risk of 'rollover'?

For example, I know of clocks that have a dual-port ram between the
actual internal clock registers and the registers that appear in the
address space. You can disable/enable updating the dual-port ram,
thereby allowing the muliple clock registers to be read without risk
of 'rollover'.

As best as I can determine, there are bits that will start/stop the
lpc2138 clock. Are these really bits that enable/disable a dual port
ram, or does it really stop the clock?

It it really stops the clock then that is unfortunate.

A workaround is to run a sub-second timer routine that reads the
second counter, waiting for it to increment, then you can read the
rest of the consolidated registers without fear of rollover.

ebarker123

Umm...  Why not just setup the second tick interrupt from RTC??
Store/Update Time/Date value every second to somewhere.

Background task (Non-ISR code) remembers to disable interrupt
when reading the Time/Date data structure..    Help??  :)

--- In lpc2000@yahoogroups.com, "ebarker123" <ebarker123@...> wrote:

> A workaround is to run a sub-second timer routine that reads the
> second counter, waiting for it to increment, then you can read the
> rest of the consolidated registers without fear of rollover.
> 
> ebarker123

That would certainly solve the problem. What I'm really interested in
knowing (so that probably makes this a Phillips question) is whether
or not the enable is opens and closes a dual-port ram, or does it
realy stop the clock.

Ed


--- In lpc2000@yahoogroups.com, "unity0724" <unity0724@...> wrote:

>
> Umm...  Why not just setup the second tick interrupt from RTC??
> Store/Update Time/Date value every second to somewhere.
> 
> Background task (Non-ISR code) remembers to disable interrupt
> when reading the Time/Date data structure..    Help??  :)
> 
> --- In lpc2000@yahoogroups.com, "ebarker123" <ebarker123@> wrote:
> > A workaround is to run a sub-second timer routine that reads the
> > second counter, waiting for it to increment, then you can read the
> > rest of the consolidated registers without fear of rollover.
> > 
> > ebarker123
>