ZAMC4100 Datasheet, PDF (44/155 Pages) Integrated Device Technology – Actuator and Motor Controller

ZAMC4100 Datasheet
3.5.2. SLEEP Mode
In SLEEP Mode, current consumption is very low, less than 80µA. The MCU chip is powered-down and the SBC
supports only the functionality necessary for detecting a LIN wake-up or WDT wake-up event (see section 3.5.4).
In this mode, all drivers are automatically disabled. The MCU enables SLEEP Mode by setting the SLEEP bit in
the SMDCTRL register (Table 3.5). SLEEP Mode is exited if the SBC detects a wake-up event from the LIN bus
and consequently it re-activates the MCU as well as re-enabling the drivers.
Figure 3.7 shows the system behavior when the SLEEP Mode is enabled. The procedure starts with switching-off
the MCU supply and SBC analog blocks supply. In order to minimize power consumption, the SBC digital clock
switches to the OSCL (125kHz).
Important note: If there is a failure in the OSCL (see section 3.2), the SLEEP Mode entry command is ignored.
As a result, the system avoids undefined states with a powered-off MCU but with power supplied for the analog
circuitry (see SLEEP Mode entry flow in Figure 3.7).
When a valid LIN wake-up is detected, the SBC chip starts the procedure for returning to the NORMAL Mode.
During this procedure, the analog blocks are powered-up, the SBC digital clock is switched to 4MHz, and the
MCU supply is enabled. Before enabling the MCU clock and releasing the MCU reset, the SBC performs an MCU
supply check that is the same as the checks at system start-up. If the MCU supply voltages are in range, it starts
operating; otherwise the system switches back to SLEEP Mode.
Important notes:
1) Activation of a driver immediately after wake-up from Sleep Mode is not possible due to the relatively slow
settling time of the charge pump (see parameter t_{CP_STL} in Table 1.17). The CP condition is continuously
monitored by the CPVEIF flag, which can be auto-cleared when a stable CP voltage is present if that
functionality is enabled. Refer to section 3.4.4 for more details regarding charge pump voltage monitoring.
2) When SLEEP Mode is enabled, all drivers are automatically disabled. If needed, after wake-up the MCU
should re-enable the drivers by setting the corresponding enable bits.
© 2016 Integrated Device Technology, Inc.
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January 26, 2016