Specific of programming Atmel 8051 microcontrollers

Microcontrollers of the Atmel 8051 family (AT89 series) can be programmed in-system being under a normal Vcc voltage. Practically all these microcontrollers require clocking while they are under in-system programming. ChipProg programmers are capable to send clocks to the target microcontroller but sometimes the systems based on the Atmel 8051 microcontrollers have their own built-in clock generators.

1.If the system has its own built-in clock generator then make sure that the clock line of the ChipProg cable adapter is not connected to the clock input pin of the target microcontroller, otherwise it may destroy either the target or programmer hardware.

2.If the target system does not have its own built-in clock generator then, the target device needs to get clocks from the ChipProg built-in generator; thus the clock output wire of the cable-adapter should be connected to an appropriate clock input pin of the target device.