Extract Firmware from MCU Microchip PIC16F627 after unlock microcontroller PIC16F627 and disable the security fuse bit by decapsulating the silicon package of chip;

Since the time-outs occur from the POR pulse, if MCLR is kept low long enough, the time-outs will expire. Then, bringing MCLR high will begin execution immediately. This is useful for testing purposes or to synchronize more than one PIC16F627 device operating in parallel when copying microchip pic16f59 program.

Table 16-5 shows the Reset conditions for some special registers, while Table 16-5 shows the Reset conditions for all the registers.

The Power Control (PCON) register (address 8Eh) has two Status bits to indicate what type of Reset that last occurred. Bit 0 is BOR (Brown-out Reset). BOR is unknown on Power-on Reset. It must then be set by the user and checked on subsequent Resets to see if BOR = 0, indicating that a Brown-out has occurred.

The BOR Status bit is a “don’t care” and is not necessarily predictable if the brown-out circuit is disabled (BOREN<1:0> =00 in the Configuration Word register). Bit 1 is POR (Power-on Reset). It is a ‘0’ on Power-on Reset and unaffected otherwise before reading out microcontroller pic16f690 program.

The user must write a ‘1’ to this bit following a Power-on Reset. On a subsequent Reset, if POR is ‘0’, it will indicate that a Power-on Reset has occurred (i.e., VDD may have gone too low). For more information, The Interrupt Control (INTCON) register and Peripheral Interrupt Request 1 (PIR1) register record individual interrupt requests in flag bits. The INTCON register also has individual and global interrupt enable bits. A Global Interrupt Enable bit, GIE (INTCON<7>), enables (if set) all unmasked interrupts, or disables (if cleared) all interrupts.

Individual interrupts can be disabled through their corresponding enable bits in the INTCON register and PIE1 register. GIE is cleared on Reset. The Return from Interrupt instruction, RETFIE, exits the interrupt routine, as well as sets the GIE bit, which re-enables unmasked interrupts.

The following interrupt flags are contained in the INTCON register:

• INT Pin Interrupt
• PORTB Change Interrupt
• TMR0 Overflow Interrupt

The peripheral interrupt flags are contained in the special registers, PIR1 and PIR2. The corresponding interrupt enable bit are contained in the special registers, PIE1 and PIE2 before reading locked pic16f916 flash.

The following interrupt flags are contained in the PIR1 register:

EEPROM Data Write Interrupt

A/D Interrupt

USART Receive and Transmit Interrupts

Timer1 Overflow Interrupt

CCP1 Interrupt

SSP Interrupt