Lpc2000

For ISP the PLL is not active after a reset. The baudrate can be 
calculated for a given frequency range. But during runtime, 
reflashing uses IAP (In Application Programming) calls. The PLL could 
be on or off. The timing for Flash programming is critical and 
everybody wants to have a fast programming algorithm. So asking us 
users for the frequency seems quite resonable to do!?

Cheers, Bob

--- In lpc2000@yahoogroups.com, Robert Adsett <subscriptions@a...> 
wrote:
> At 10:23 PM 11/17/04 +0000, you wrote:
> >Why is the oscillator frequency needed in the first place? Isn't 
the
> >interface baud rate detected by the bootloader?
> 
> Timing, They need to know the speed of the clock so they can 
determine the 
> timing for programming the flash.  IE 6 counts at 20Mhz and 12 
counts at 
> 10MHz in some internal timing loop.
> 
> The information has to come from somewhere.  The Analog Devices 
chips don't 
> need it (in a similar case) since they only allow a single Xtal 
frequency.
> 
> Robert
> 
> " 'Freedom' has no meaning of itself.  There are always 
restrictions,
> be they legal, genetic, or physical.  If you don't believe me, try 
to
> chew a radio signal. "
> 
>                          Kelvin Throop, III