Verdin Carrier Board Design Guide
Preliminary
– Subject to Change
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3.3.9
“Module OFF” to “No VCC” (power off after shutdown)
Figure 56: “Module OFF” to “No VCC” (power off after shutdown) Power Sequence
As described in section 3.3.6 “Running” to “Module OFF” (shutdown), the CTRL_PWR_BTN_MICO#
goes low after a certain time after the last rail was removed. Depending on the module, this delay
can be several seconds. If a carrier board uses the CTRL_PWR_BTN_MICO# signal for killing the
main module voltage rail VCC, the system will transition to the “No VCC” state. This means the
VCC is removed from the module.
The only rail that is still optionally supplied to the module is the VCC_BACKUP rail for the on-
module real time clock. The carrier board should avoid of having any signal driving high that is
connected to the module to prevent back feeding.
3.3.10
Remove VCC in any power state
If the main module power rail is removed in any power state, the different power rails are shut
down in a non-graceful order. This should not physically damage the module. However, the flash
memory may get corrupted. Therefore, the removal of the VCC should be avoided if the system
was not shut down properly in advance.
VCC_BACKUP
VCC
Early Module Rails
PWR_1V8_MOCI#
Carrier Board rails
Later Module Rails
Module Peripherals
CB Sleep Peripherals
CTRL_PWR_BTN_MICO#
CTRL_RESET_MICO#
CTRL_PWR_EN_MOCI
CTRL_SLEEP_MOCI#
CTRL_FORCE_OFF_MOCI#
CTRL_WAKE1_MICO#
SoC RESET
CTRL_RESET_MOCI#
