We can Recovery CHIP ATMEGA2560PV Program, please view the CHIP ATMEGA2560PV features for your reference:
In this example, Timer/Counter2 provides the carrier, while the modulating signal is generated by the Output Compare unit C of the Timer/Counter1 when Recovery CHIP program.
The resolution of the PWM signal (OC1C) is reduced by the modulation. The reduction factor is equal to the number of system clock cycles of one period of the carrier (OC0A).
In this example the resolution is reduced by a factor of two. The reason for the reduction is illustrated in Figure 66 at the second and third period of the PB7 output when PORTB7 equals zero if Recovery CHIP program.
The period 2 high time is one cycle longer than the period 3 high time, but the result on the PB7 output is equal in both periods. Timer/Counter2 is a general purpose, single channel, 8-bit Timer/Counter module. The main features are before Recovery CHIP program:
Single Channel Counter
Clear Timer on Compare Match (Auto Reload)
Glitch-free, Phase Correct Pulse Width Modulator (PWM) after Recovery CHIP program
Frequency Generator
10-bit Clock Prescaler
Overflow and Compare Match Interrupt Sources (TOV2, OCF2A and OCF2B)
Allows Clocking from External 32 kHz Watch Crystal Independent of the I/O Clock
A simplified block diagram of the 8-bit Timer/Counter is shown in Figure 60.. For the actual placement of I/O pins, see “Pin Configurations” on page 2. CPU accessible I/O Registers, including I/O bits and I/O pins, are shown in bold. The device-specific I/O Register and bit locations are listed in the “8-bit Timer/Counter Register Description” on page 184 if Recovery CHIP program.
The Power Reduction Timer/Counter2 bit, PRTIM2, in “Power Reduction Register 0 – PRR0” on page 54 must be written to zero to enable Timer/Counter2 module before Recovery CHIP program.
The Timer/Counter (TCNT2) and Output Compare Register (OCR2A and OCR2B) are 8-bit registers. Interrupt request (abbreviated to Int.Req.) signals are all visible in the Timer Interrupt Flag Register (TIFR2). All interrupts are individually masked with the Timer Interrupt Mask Register (TIMSK2). TIFR2 and TIMSK2 are not shown in the figure when Recovery CHIP program.
The Timer/Counter can be clocked internally, via the prescaler, or asynchronously clocked from the TOSC1/2 pins, as detailed later in this section. The asynchronous operation is controlled by the Asynchronous Status Register (ASSR). The Clock Select logic block controls which clock source the Timer/Counter uses to increment (or decrement) its value. The Timer/Counter is inactive when no clock source is selected. The output from the Clock Select logic is referred to as the timer clock (clkT2). The double buffered Output Compare Register (OCR2A and OCR2B) are compared with the Timer/Counter value at all times after Recovery CHIP program.
The result of the compare can be used by the Waveform Generator to generate a PWM or variable frequency output on the Output Compare pins (OC2A and OC2B). See “Output Compare Unit” on page 175. for details.
The compare match event will also set the Compare Flag (OCF2A or OCF2B) which can be used to generate an Output Compare interrupt request. Many register and bit references in this document are written in general form. A lower case “n” replaces the Timer/Counter number, in this case 2. However, when using the register or bit defines in a program, the precise form must be used, i.e., TCNT2 for accessing Timer/Counter2 counter value and so on before Recovery CHIP program.
The definitions in Table 84 are also used extensively throughout the section.