Dell E176FPc5012. ISP (In System Program) User Manual12.1 Connect ISP Writer preparation actionConnect RXD and TXD of PC to RXD (P3.0) and TXD (P3.1) of CPU through RS-232.a. There are two ways to entering Reboot Mode. The settings for Reboot Mode is as followz Both P2.6 P2.7 are LOW and RESET pin is HIGHT.z P4.3 is LOW and RESET pin is HIGHT.