NXP Semiconductors MKW01Z128, Reference Manual, Page: 683 / 884

// Timer 1
PIT_LDVAL1 = 0x23C345FF; // setup Timer 1 for 600 000 000 cycles
PIT_TCTRL1 = TEN; // start Timer 1
28.7 Example configuration for the lifetime timer
To 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 CTRL
register, 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 PIT
PIT_MCR = 0x00;
// Timer 1
PIT_LDVAL1 = 0xFFFFFFFF; // setup timer 1 for maximum counting period
PIT_TCTRL1 = 0x0; // disable timer 1 interrupts
PIT_TCTRL1 |= CHN; // chain timer 1 to timer 0
PIT_TCTRL1 |= TEN; // start timer 1
// Timer 0
PIT_LDVAL0 = 0xFFFFFFFF; // setup timer 0 for maximum counting period
PIT_TCTRL0 = TEN; // start timer 0
To access the lifetime, read first LTMR64H and then LTMR64L.
current_uptime = PIT_LTMR64H<<32;
current_uptime = current_ PIT_LTMR64L;
Example configuration for the lifetime timer
MKW01Z128 MCU Reference Manual, Rev. 3, 04/2016
552 Freescale Semiconductor, Inc.