The Digi Microcontroller Assist™ hardware
ConnectCore® 8X System-on-Module Hardware Reference Manual
36
Watchdog
The MCA implements a watchdog timer in its firmware. The MCA watchdog resets the system, or only
the i.MX 8X CPU, if the software running on the main processor fails to execute properly and does not
reset the watchdog timer on time.
The main features of the MCA watchdog include:
n
Configurable timeout between 1 and 255 seconds.
n
Configurable to generate interrupt or system reset.
n
Configurable to generate full-system reset (including the MCA itself) or CPU-only reset. Full-
system reset can include a PMIC off/on, depending on the device configuration.
See the
for additional information about how to configure and access
the watchdog timer.
Real-time clock
The MCA implements a Real-Time Clock (RTC) in its firmware. The i.MX 8X CPU internal RTCs are
disabled by default because the MCA RTC is preferred due to its superior power consumption
efficiency. To preserve the date during power-off, you must connect a coin cell battery following the
design notes provided in
System-on-module power rails distribution
.
The main features of the MCA RTC include:
n
Date/time registers to keep the system time (backed up by the coin cell battery).
n
Programmable alarm to generate an interrupt. This alarm can be used to wake the system
from low power modes (suspend and power off).
See the
for additional information about how to configure and access
the watchdog timer.
Pulse width modulation
Pulse-width modulation (PWM) is a technique that modifies the duty cycle of a pulsing signal to
encode information or to control the amount of energy provided to a charge. The MCA implements
pulse-width modulation in its firmware.
The MCA on the ConnectCore 8X system-on-module provides three PWM controllers. Each controller
has several channels and each channel maps to one MCA IO pin:
PWM controller Number of channels Channel
IO
PWM0
6
0
MCA_IO0
1
MCA_IO12
2
MCA_IO15
3
MCA_IO16
4
MCA_IO17
5
MCA_IO18
