Copy Chip PIC16LF777 Software from its memory include the flash and eeprom, break microcontroller and disable its security fuse bit and dump the firmware out in the format of heximal;

In the Full-Bridge mode, the P1M1 bit in the CCP1CON register allows users to control the forward/reverse direction. When the application firmware changes this direction control bit, the module will change to the new direction on the next PWM cycle.

A direction change is initiated in software by changing the P1M1 bit of the CCP1CON register. The following sequence occurs four Timer2 cycles prior to the end of the current PWM period if copy microcontroller pic16lf737 eeprom:

• The modulated outputs (P1B and P1D) are placed in their inactive state.
• The associated unmodulated outputs (P1A and P1C) are switched to drive in the opposite direction.
• PWM modulation resumes at the beginning of the next period.

See figures for an illustration of this sequence. The Full-Bridge mode does not provide dead-band delay. As one output is modulated at a time, dead-band delay is generally not required. There is a situation where dead-band delay is required.

This situation occurs when both of the following conditions are true:

The direction of the PWM output changes when the duty cycle of the output is at or near 100%. The turn off time of the power switch, including the power device and driver circuit, is greater than the turn on time when microcontroller pic16f777 heximal reading.

Figure 11-13 shows an example of the PWM direction changing from forward to reverse, at a near 100% duty cycle. In this example, at time t1, the output P1A and P1D become inactive, while output P1C becomes active. Since the turn off time of the power devices is longer than the turn on time, a shoot-through current will flow through power devices QC and QD (see Figure 11-10) for the duration of ‘t’.

The same phenomenon will occur to power devices QA and QB for PWM direction change from reverse to forward. If changing PWM direction at high duty cycle is required for an application, two possible solutions for eliminating the shoot-through current are:

Reduce PWM duty cycle for one PWM period before changing directions. Use switch drivers that can drive the switches off faster than they can drive them on. Other options to prevent shoot-through current may exist. When any PWM mode is used, the application hardware must use the proper external pull-up and/or pull-down resistors on the PWM output pins.