Fw: pdf file using xsl

Hello,
I tried this message earlier but it bounced back. I am new to this
 I am working on an application which requires me to generate a pdf file 
of up to 200MB size. I tried generating xml file and then apply xsl on it 
with the Apache FOP driver.
 
The result is "Out of Memory" error. I am not sure where the out of memory 
error is coming, in FOP code or in Saxon8(I am using Saxon processor and 
XSLT 2.0).
 
Could anyone please help me out and let me know what could be wrong.
 
PS: I have already tried to increase the JVM memory (-Xms218m -Xmx512m).
 
Regards.
Neeraj