Extract Microchip PIC16F684 Locked Microprocessor Software

Extract Microchip PIC16F684 Locked Microprocessor Software and copy embedded firmware to new microcontroller pic16f684 flash memory, after that engineer can recover the original schematic from pcb board;

In addition to temperature tolerance, the effective capacitance of large value ceramic capacitors can vary substantially, based on the amount of DC voltage applied to the capacitor. This effect can be very significant, but is often overlooked or is not always documented. A typical DC bias voltage vs. capacitance graph for X7R type capacitors is shown in Figure 2-4.

When selecting a ceramic capacitor to be used with the internal voltage regulator, it is suggested to select a high- voltage rating so that the operating voltage is a small percentage of the maximum rated capacitor voltage. For example, choose a ceramic capacitor rated at a minimum of 16V for the 1.8V core voltage. Suggested capacitors are shown in Table 2-1.

The PGECx and PGEDx pins are used for In-Circuit Serial Programming™ (ICSP™) and debugging purposes. It is recommended to keep the trace length between the ICSP connector and the ICSP pins on the device as short as possible. If the ICSP connector is expected to experience an ESD event, a series resistor is recommended, with the value in the range of a few tens of ohms, not to exceed 100Ω.