PIC microcontroller learning TMR2

The 8-bit TMR2 timer has a pre-prescaler and a post-prescaler, and a cycle control register that works together with it to count the instruction cycles of the microcontroller.

TMR2 can only be used as a timer and cannot count external input pulses.

The biggest difference between TMR2 timer and TMR0 is that TMR2 has a cycle control register PR2. The PR2 register can set the upper limit of the timer. As long as the count value of TMR2 is equal to the set value of PR2, it will automatically return to 0 and generate an interrupt.

When the count value of TMR2 matches the value set in the PR2 register, the arrival of a count pulse should cause TMR2 to overflow to 0. Note: After a count overflows to 0, the TMR2IF interrupt flag is not necessarily generated immediately. When the interrupt flag is generated depends on the division ratio of the post-divider. If the selected post-divider ratio is 1:8, an interrupt will be generated only after TMR2 overflows 8 times.

//Pre-divider 
//T2CKPS1 T2CKPS0 
// 0 0 1 division TMR1 clock is crystal clock/(4*1) 
// 0 1 4 division TMR1 clock is crystal clock/(4*4) 
// 1 x 16 division TMR1 clock is crystal clock/(4*16) 
//Post-divider 
//TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 
// 0 0 0 0 1 division 
// 0 0 0 1 2 division 
// 0 0 1 0 3 division 
// 0 0 1 1 4 division 
// 0 1 0 0 5 division// 0 1 0 
1 6 division 
// 0 1 1 0 7 division 
// 0 1 1 1 8 division 
// 1 0 0 0 9 division 
// 1 0 0 1 10-way division 
// 1 0 1 0 11-way division 
// 1 0 1 1 12-way division 
// 1 1 0 0 13-way division 
// 1 1 0 1 14-way division 
// 1 1 1 0 15-way division 
// 1 1 1 1 16-way division