Hi I want to use dual DPTR on my 89c669 from Philips. When i insert the pragma
#pragma modp2
I know nothing about the device you are using but a quick search of Keil's website turned up this document that appears to apply to your problem. http://www.keil.com/support/docs/2576.htm
It makes no sense to use dual DPTR with a Philips MX device like the 669. The 669 offers hardware support for the 3-byte pointers and by default the CX51 compiler uses already two register pairs in several library functions. So there is no benefit for using the dual DPTR stuff and you should take it out.