FreeMASTER Control Page
KIT33912EVME System Basis Chip with LIN Tranceiver Setup Instructions, Rev. 2.0
Freescale Semiconductor
13
Figure 3-4. Watchdog Control Buttons
3.7
Wake-up Sources
The MC33912 device offers two low power modes, Stop and Sleep, with various wake-up capabilities. There are three wake-up
events, which require setup before entrance to the low power modes; see
. To set a wake-up from the wake-up inputs
L1, L2, L3, L4 without cyclic sensing, select button
Lx
. To set a cyclic sense timer and wake-up inputs L1, L2, L3, L4, press button
Cyclic
. To set a forced wake-up, choose
Forced
.
After clicking one of the wake buttons, all unnecessary control units are disabled and the low power buttons
Stop
and
Sleep
are
enabled. If the user enters the wrong wake-up settings and places the mouse over the low power buttons, the invalid cell will be
red and a help hint will be displayed in the Last Error Message panel.
A forced wake-up requires the High Side Switch outputs disabled and a predetermined low power period. This period is selectable
in a drop down menu. On first use, the period value must be changed to a setting corresponding to bits in the TIMCR register.
Before entering low power modes with cyclic sensing, the following setup has to be performed. Select Lx inputs, enable HSx
outputs and predetermine the cyclic sense period.
In order to select and activate direct wake-up from the Lx inputs, those inputs must be enabled.
When all the required wake-up set-up has been done and the user presses the
Stop
or
Sleep
buttons, the status of the important
registers (WUCR, HSCR, TIMCR, CFR, MCR) will be send to the device. The device will then enter one of the low power mode.
Figure 3-5. Wake-up Configuration Panel
