Lpc2000

Hi Kerem,

This is actually a bug which is related to the EXTINT.1 bug (present 
in the Errata sheet). 

Problem: Incorrect setting of EXTMODE and/or EXTPOLAR register while 
trying to set them to desired value. 

For instance, trying to set EXTMODE to 0x1 or 0xd would result in 
EXTMODE to be set to 0x0 instead. To avoid this problem, while 
writing to EXTMODE and/or EXTPOLAR the following steps have to be 
carried out.

Workaround: 
Since this issue is related to the EXTINT.1 Errata, the same 
workaround applies with an additional step.

Before writing to the EXTMODE and EXTPOLAR registers,
1> Write 0x0 to VPBDIV 
2> Then write the desired value to EXTMODE or EXTPOLAR register. 
3> Then write the same value to VPBDIV ( additional step)
4> Restore the VPBDIV to the previously saved value or simply write 
to the register again with the desired value.

Note:
While testing this in a debugger enviornment, please dont single-step 
through these steps. A breakpoint could  be placed after Step 4 and 
you would see the EXTMODE and EXTPOLAR registers reflecting the 
correct values.

The Errata sheet for these devices will be updated soon. This bug is 
not present in the LPC213x.

Thanks
Philips_apps



--- In lpc2000@yahoogroups.com, "Kerem Or" <k.or@s...> wrote:
> 
> Dear Philips Apps people,
> 
> LPC2214 fails to write 0x0d to EXTMODE register even when VPBDIV=0 
> as advised in the device errata. The EXTMODE register prior to 
write 
> was 0x0f and gets 0x00 just after attempting to set to 0x0d.
> 
> What happens is in conflict with the workaround suggested in the 
> device errata.
> 
> Please advise...
> 
> Device marking
> ---------------
> LPC2214FBD144
> CD0931 05
> TS0432A
> 
> Kerem Or,
> SYS Inc.