Verdin Carrier Board Design Guide
Preliminary
– Subject to Change
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module. The Verdin module is then enabling the peripheral power rails on the carrier board by
asserting the CTRL_PWR_EN_MOCI signal. There is an optional pull-down resistor on the
CTRL_PWR_EN_MOCI signal. This resistor makes sure the power supplies are not turning on if
there is no module inserted. However, this is not required for a carrier board that is never to be
operated without a Verdin module.
In this example, the carrier board creates 1.8V, 3.3V, and 5V for the peripherals. For the 1.8V and
the 3.3V, there are buck converters on the carrier board which are enabled by the
CTRL_PWR_EN_MOCI signal. Since there is already a buck converter for the main 5V VCC rail,
there is only a switch required for the peripheral 5V rail. In this approach, the PWR_1V8_MOCI is
not used since there is a dedicated 1.8V buck on the carrier board.
If the module is running, a short pressing of the power button will generate an interrupt output at
the power button control IC. This interrupt is connected to the CTRL_PWR_BTN_MICO# input of the
module. A falling edge on this input will cause a software interrupt. Depending on the
configuration, the OS will then start shutting down the software and ramping down power rails on
the module. The module is asserting the CTRL_FORCE_OFF_MOCI# signal which kills the enable
output of the power button control IC. This disables the main 5V VCC rail.
If the module is running, a long pressing of the power button (>5s) is generating an emergency
power shutdown of the system. The power button control IC is forwarding the long press event to
the CTRL_PWR_BTN_MICO# input of the module PMIC. The PMIC is shutting down all power rails
without software interaction. At the end, the CTRL_FORCE_OFF# is asserted which turns off the
main 5V regulator.
3.4.1.2
System Power States
Figure 58: System Power States and Transitions
Compared to the module power states found in section 3.2, the system does not have a “Module
OFF” state. This module state is only temporary since carrier board uses to kill the VCC when the
module is asserting the CTRL_FORCE_OFF_MOCI# as a final act in the shutdown and force OFF
cycle.
The system is booted by turning on the main VCC rail of the module by the power button IC on the
carrier board. This power button IC has an interrupt output which is used to get the power button
press information to the Verdin module by connecting it to the CTRL_PWR_BTN_MICO# input. The
power button IC on the carrier board features also a shut down by long pressing the button. It is
Running
PWR_EN_MOCI =1
SLEEP_MOCI# =1
RESET_MOCI# =1
FORCE_OFF_MOCI# =1
Sleep
PWR_EN_MOCI =1
SLEEP_MOCI# =0
RESET_MOCI# =1
FORCE_OFF_MOCI# =1
Reset
PWR_EN_MOCI =0**
SLEEP_MOCI# =0**
RESET_MOCI# =0
FORCE_OFF_MOCI# =1
No VCC
PWR_EN_MOCI =0
SLEEP_MOCI# =0
RESET_MOCI# =x
FORCE_OFF_MOCI# =x
Turn on VCC
VCC > 3.135V
Remove VCC
VCC < 0.5V
Run to Reset
Software initiated Reset
or
RESET_MICO# = 0
Reset to Run
RESET_MICO# = 1
Run to Sleep
Software initiated Sleep
Sleep to Run
WAKE1_MICO# = 0
or
PWR_BTN_MICO# = 0 (<5s)
Force Off
PWR_BTN_MICO# = 0 (>5s)
Shutdown
Software initiated power down*
From any State
* Can also be initiated by
PWR_BTN_MICO# = 0 (<5s)
** Depends on the Module
