COMe-bTL6 - User Guide. Rev. 1.5
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3.15.
UART
The UART serial communications interface supports up to two serial RX/TX ports supplied by the chipset. The two
serial ports are defined in the COMe specification on pins A98 (SERO_TX) and A99 (SERO_RX) for UART0, and pins
A101 (SER1_TX) and A102 (SER1_RX) for UART1.
Optionally it is possible that the two serial RX/TX ports are generated
by the Embedded Controller.
Two serial RX/TX ports from the chipset (PCIe based, non-legacy, no RTS/CTS) with an
option for two UART serial RX/TX ports from the Embedded Controller.
3.16.
Watchdog Timer (WTD
) Dual Stage
The watchdog timer interrupt is a hardware or software timer implemented by the module to the carrier board if
there is a fault condition in the main program; the watchdog triggers a system reset or other corrective actions after a
specific time, with the aim to bring the system back from a non-responsive to normal state.
The COMe-bTL6 supports an independently programmable watchdog that works with two stages that can be used
stage by stage.
Table 34: Dual Staged Watchdog Timer- Time-Out Events
0000b
No action
Stage is off and will be skipped
0001b
Reset
Restarts the module and starts a new POST and operating system
0101b
Delay -> No action
Might be necessary when an operating system must be started and the time for
the first trigger pulse must be extended. Only available in the first stage!
1000b
WDT Only
Triggers WDT pin on the carrier board connector (COM Express® pin B27) only
1001b
Reset + WDT
1101b
DELAY + WDT -> No
action
3.16.1.
Watchdog Timer Signal
The watchdog interrupt (WDT) on COM Express® pin B27 on COM Express® connector indicates a Watchdog time-out
event has not been triggered within a set time. The WDT signal is configurable to any of the two stages. After reset,
the signal is automatically de-asserted. If de-assertion is necessary during runtime, contact Kontron Support for
further help.
3.17.
XDP (option)
The XDP debug connector is used for development.