Lpc2000

Hi,

What possibilities, are there to increase the performance. 
I need to process many instructions at my UART
interrupt-service-routine. So I get problems at higher Baud rates. 
I use the 14,745 MHz quartz, and don�t want to use the PLL (to save
current); pclk = cclk. 
I compiled the called functions in thumb mode, and optimized the output
with level 3. 
I reached a better performance, but are there other ways to get higher? 

Thanks S�ren