It is givving an error saying that " *** error 65: access violation at D15:0x96 : no 'write' permission" it is not updating the page regester to change pages.
Keil shows the error for this part of code compilation. And the Timers (3 and 4) in peripheirals are not updated in simulation mode .. SFRPAGE = TMR3_PAGE; TMR3CN = 0x07 ; SFRPAGE = TMR4_PAGE; TMR4CN = 0x07 ; we are using Keil 8.00v (eval). But the code worked properly in 7.50a ver (full) ..but the problem there was that the peripherials window was not active i.e., The peripherals where not availabe( No timers etc.) to use except -- Reset CPU. The code is for Silicon labs ..C8051F120