Device
and operation
CPC307
C P C 3 0 7 U s e r M a n u a l
67
© 2 0 2 2 F a s t w e l v . 0 0 6
6Ch
7:0
R/W
Bits [23:16] of WDT1 timer, resolution
– 30.5
µs
WDT1 state register
(value after 00h reset)
6Dh
7
R/WC
WDT1 timer status flag
0
– timer was not triggered
1
– timer was triggered (writing “1” to this bit resets the
flag)
6:0
RO
Reserved
4.3.15.2 WDT2 watchdog timer
The WDT2 watchdog functions are performed by the ADM706T chip. The timer functions are
controlled through GPIO1 lines 1, 2, 3, 4 of the Vortex86DX SoC chip:
GPIO1 line 1 (output) - WDT2 watchdog timer reset;
GPIO1 line 2 (output)
– Enabling WDT2 watchdog timer. “1” - enabled, “0” - disabled;
GPIO1 line 3 (output) - In module version 1.0 this pin is not used (Watchdog state trigger resets to
“0”);
GPIO1 line 4 (input) - Watchdog state.
“1” - was triggered, “0” - was not triggered.
In module versions lower than 4.x, the WDT2 watchdog timer can be hardware disabled by setting
a jumper to the XP26 connector. In module versions 4.x, the opposite is true: setting a jumper to
the XP26 enables the WDT2 watchdog timer, while removing the jumper disables it.
For a more detailed description of GPIO ports see paragraph
4.3.19 GPIO Ports
.
4.3.16 RTC, CMOS, FRAM, hardware reset and BIOS backup
Standard, IBM PC-compatible real time clock (RTC - Real Time Clock) is used in the module.
Clock operation in the off state of the module is provided by a 3V CR2032 (Renata) DC battery,
installed in the X1 holder.
Attention!
In order to ensure the accuracy of the real time clock, it is recommended to
synchronize it with the accurate readings at least once a day. It is recommended to
synchronize the real time clock after transportation and storage.
4.3.16.1 BIOS backup
Two copies of BIOS are stored in the module (for versions lower than 4.x) - the main and backup
BIOS. When you turn on the power supply the module always boots from the main BIOS copy. In
the event of actuation of the external watchdog in the ADM706T power supply supervisor chip, the
module will restart.
If the XP21 jumper is removed, the module is always booted from the main BIOS copy (paragraph
4.3.20 Configuration jumpers
). When the XP21 jumper is installed and the watchdog timer is
triggered the module will restart from the BIOS backup copy. Further watchdog triggering will also
be done from the backup copy.
When booting from the BIOS backup copy, you can resume booting from the main copy by one of
the following ways: