ISP probl

[Ren]

Y use Flashmagic with a LPC922, and y arrive to go in ISP mode with "Use DTR / RTS to enter ISP mode" when my application works with the RC oscillators, but y can'not arrive when y use an external oscillators with the same application.

Some one can help me for this problem ?

[erikm]

there is something somewhere about problems when using a clock higher than the internal.  I have no exact recollection, do a search.

Erik

[Andy Ayre]

You have to select an external oscillator option in the device configuration (UCFG1) if you haven't do so already.
If your crystal frequency is slower the 7.37MHz, then you will likely need to use a baud rate of 4800 or even 2400 baud.
Have you checked the signals on the XTAL pins?

[Bauke Siderius]

Hi,

The first thing I would do is check with a scope that you acctually have a clock signal with an external crystal.

Erik, I'm not aware of any problems using a higher clock signal, this should work the same as with the internal RC oscillator.
A slower clock rate than the internal RC oscillator's 7.37MHz would make the autobauding slower.

Regards,

Bauke