Reset Control - Digi ConnectCore 8X Hardware Reference Manual

The ConnectCore 8X System-on-Module
Pad name
LGA /
Castellated
pads
AN22 / 53
AN23 / 54
AN24 / 55
AN25 / 56
AN26 / 57

Reset control

The MCA, in cooperation with the PMIC, controls the reset line of the i.MX 8X processor. The SYS_
RESET pin is the main reset input of the ConnectCore 8X module. This pin is a pseudo open-drain with
an internal pull up. Asserting the SYS_RESET line low sets the MCA into reset state, and it remains in
this state until the line is de-asserted.
During system initialization, the MCA performs the following actions:
Asserts the PMIC on/off line (SCU_PMIC_ON_REQ) low for a configurable time (0-255 ms with a
n
default value of 50ms). This powers the PMIC off, switching off all regulated outputs of the
PMIC. You can disable this power cycle by setting the timer to 0.
Asserts the PMIC on/off line high to power the system on.
n
Keeps the reset line of the CPU low for a configurable time.
n
Releases the reset line of the CPU to allow starting the execution of the firmware on the i.MX
n
8X processor.
Note The CPU reset line is also connected to the PMIC. The PMIC won't release this line until it
is switched on and the entire starting sequence is finished (a few ms after the latest regulator
is turned on). This means that even if the MCA releases the reset line before the PMIC is ready,
the CPU won't go out of reset.
The following time diagram represents the reset sequence. Default values are as follows:
tr : 50 ms
n
1
tr : 2 ms
n
2
ConnectCore® 8X System-on-Module Hardware Reference Manual
ConnectCore 8X
signal name Pin direction
MCA_IO2 Bi-directional
MCA_IO3 Bi-directional
SWD_CLK/PWR_IO Input
SYS_RESET Input
SWD_DIO/MCA_IO0 Bi-directional
The Micro Controller Assist™ hardware
Type Definition
Digital General purpose
Input/Output
Digital General purpose
Input/Output
Digital Power on/off linput line,
active low. SWD interface
clock line.
Digital Reset input line of the MCA,
active low. It is also the
input reset line of the whole
ConnectCore 8X SOM.
Digital General purpose
Input/Output. SWD
itnerface date line.
30