How can I optimize the xdata access with C51

Hi there! I need to optimize the accessing the xdata memory (the speed) with C51. I am sending some files via modem and the transmission could be a bit faster. At present, I am reaching a transmission...
How can I optimize the xdata access with C51

Hi there! I need to optimize the accessing the xdata memory (the speed) with C51. I am sending some files via modem and the transmission could be a bit faster. At present, I am reaching a transmission...
xdata access, how ?

Dear sir, i am is a student in physic department,i use uVision IDE for 8051 ver 6.20c, build a single board computer, with core is AT89S52,one Dallas RTC 12C887,and an 8255 PPI, both (RTC & PPI) connected...
xdata access, how ?

Dear sir, i am is a student in physic department,i use uVision IDE for 8051 ver 6.20c, build a single board computer, with core is AT89S52,one Dallas RTC 12C887,and an 8255 PPI, both (RTC & PPI) connected...
Why I can access the xdata memory 0x38000 to 0x3FFFF but can't access 0x28000 to 0x2FFFF?

I extend the off-chip xdata memory up to 128k, and code memory 128k. But when I access xdata 0x28000 to 0x2FFFF, the MCU(w77c32) is reseted. How can I do to resolve the problem?