Microchip Technology dsPIC33F Family Instrukcja Użytkownika Pobierz pdf (Strona 19)

Section 11. Timers

Timers

11.7 32-BIT TIMER MODES OF OPERATION

11.7.1 Timer Mode

The 32-bit timer operates similarly to a 16-bit timer in Timer mode. Example 11-6 illustrates the

code sequence to set up Timer2 and Timer3 in 32-bit Timer mode.

Example 11-6: Initialization Code for 32-Bit Timer Mode

11.7.2 Gated Timer Mode

The 32-bit timer operates similarly to a 16-bit timer in Gated Timer mode. Example 11-7

illustrates the code sequence to set up Timer2 and Timer3 in 32-bit Gated Timer mode.

Example 11-7: Initialization Code for 32-Bit Gated Timer Mode

T3CONbits.TON = 0; // Stop any 16-bit Timer3 operation

T2CONbits.TON = 0; // Stop any 16/32-bit Timer3 operation

T2CONbits.T32 = 1; // Enable 32-bit Timer mode

T2CONbits.TCS = 0; // Select internal instruction cycle clock

T2CONbits.TGATE = 0; // Disable Gated Timer mode

T2CONbits.TCKPS = 0b00; // Select 1:1 Prescaler

TMR3 = 0x00; // Clear 32-bit Timer (msw)

TMR2 = 0x00; // Clear 32-bit Timer (lsw)

PR3 = 0x0002; // Load 32-bit period value (msw)

PR2 = 0x0000; // Load 32-bit period value (lsw)

IPC2bits.T3IP = 0x01; // Set Timer3 Interrupt Priority Level

IFS2bits.T3IF = 0; // Clear Timer3 Interrupt Flag

IEC0bits.T3IE = 1; // Enable Timer3 interrupt

T2CONbits.TON = 1; // Start 32-bit Timer

/* Example code for Timer3 ISR */

void __attribute__((__interrupt__, no_auto_psv)) _T3Interrupt(void)

{

/* Interrupt Service Routine code goes here */

IFS0bits.T3IF = 0; // Clear Timer3 Interrupt Flag

}