LISA-C2 series and FW75-C200 - System Integration Manual
UBX-13000620 - R21
Early Production Information
System description
Page 22 of 103
•
After 10 sec, the internal background tasks are fully initialized
It is very important to ensure the module V_INT pin is at 0V before power-on. This will ensure all
areas of the internal module are completely powered down. Failure to comply may result in
unpredictable behavior and possible memory corruption.
The following figure illustrates the power-on sequence and timing of power supply and control signals.
VCC
P WR _ON
V_INT
Internal R es et
Interface S ignals
S ys tem S tate
Interface S tate
Background
tasks loading
ON
OF F
Tristate
Internal RS T
Internal Reset
→
Operational
Start-up
event
Start of interface
configuration
PWR_ON
can be set high
50 ms
350 ms
3 s
All interfaces
are configured
0 ms
200 ms
10 s
Tasks loaded
Figure 8: Module power up timing and sequence of supply and signals
1.6.4.2
Power-on using VCC method
•
Pull
PWR_ON
pin low prior to applying VCC and wait 20 ms, or keep permanently held low
•
Ensure voltage at
VCC
pin is 0V before applying
VCC
•
Ensure voltage at
V_INT
pin is 0V before applying
VCC
•
Apply
VCC
•
Wait 300 ms (boot time)
•
Release
PWR_ON
pin back to high, or keep permanently held low
•
Modem is operational after 3 sec
•
After 10 sec, the internal background tasks are fully initialized
It is very important to ensure the module VCC pin and V_INT pin is at 0V before power-on. This
will ensure all areas of the internal module are completely powered down. Failure to comply may
result in unpredictable behavior and possible memory corruption.
1.6.4.3
Power-off
Preferred method
•
Issue
AT+CPWROFF
AT command; either via UART or USB
•
Wait for OK response
•
Wait for at least 10 sec after OK response
•
Remove
VCC
