The 100 MHz clock frequency equates to a clock period of 10 ns, so the PIT needs tocount for 6000 million cycles, which is more than a single timer can do. So, Timer 1 isset up to trigger every 6 s (600 million cycles). Timer 2 is chained to Timer 1 andprogrammed to trigger 10 times.The value for the LDVAL register trigger is calculated as number of cycles-1, soLDVAL1 receives the value 0x23C345FF and LDVAL2 receives the value 0x00000009.The interrupt for Timer 2 is enabled by setting TCTRL2[TIE], the Chain mode isactivated by setting TCTRL2[CHN], and the timer is started by writing a 1 toTCTRL2[TEN]. TCTRL1[TEN] needs to be set, and TCTRL1[CHN] and TCTRL1[TIE]are cleared.The following example code matches the described setup:// turn on PITPIT_MCR = 0x00;// Timer 2PIT_LDVAL2 = 0x00000009; // setup Timer 2 for 10 countsPIT_TCTRL2 = TIE; // enable Timer 2 interruptPIT_TCTRL2 |= CHN; // chain Timer 2 to Timer 1PIT_TCTRL2 |= TEN; // start Timer 2// Timer 1PIT_LDVAL1 = 0x23C345FF; // setup Timer 1 for 600 000 000 cyclesPIT_TCTRL1 = TEN; // start Timer 130.8 Example configuration for the lifetime timerTo configure the lifetimer timer, channels 0 and 1 need to be chained together.First the PIT module needs to be activated by writing a 0 to the MDIS bit in the CTRLregister, then the LDVAL registers need to be set to the maximum value.The timer is a downcounter.The following example code matches the described setup:// turn on PITPIT_MCR = 0x00;// Timer 1PIT_LDVAL1 = 0xFFFFFFFF; // setup timer 1 for maximum counting periodPIT_TCTRL1 = 0x0; // disable timer 1 interruptsPIT_TCTRL1 |= CHN; // chain timer 1 to timer 0PIT_TCTRL1 |= TEN; // start timer 1// Timer 0Example configuration for the lifetime timerKL27 Sub-Family Reference Manual , Rev. 5, 01/2016498 Freescale Semiconductor, Inc.
