Okay, as promised earlier in [1], here's a link to a much more detailed explanation on using PDATA with the Triscend E5 and some additional details on how the 8051 performs indirect addressing to XDATA memory.

http://portal.knowledgebase.net/article.a...7484&p=171

Reference:
[1] http://www.8052.com/forum/read.phtml?id=16146&top=