User's Manual

Screen Service SDT 200UB – SDT 500UB ARK-1 ATSC Operations
July, 2009 v 1.0 Page 3 - 107
3.8.13 Task Error Event
The watchdog performs a periodic (every 20 seconds) polling of tasks and triggers a system reset if
one or more tasks do not answer, restarting the Codeloader (See
Codeloader_Operations_Note_v1.1.doc for further information) and generating a TSK ERR event as
follows:
The blue underlined 32-bits word is the enabling status of the alarms mask. The red underlined 32-
bits word indicates the status of tasks (1 if the task has been successfully performed, otherwise 0)
as specified in the following table:
Table 21. Task error event specific data
TASK Description Bit
WD_FAN_TASK
This task controls fans speed on the base of the
board temperature.
0
WD_UPCV_TASK This task controls the Upconverter status. 1
WD_GPS_TASK This task controls the GPS status. 2
WD_STATUS_TASK
This task gathers quite all the board information in
order to perform the following operations:
•
It updates all variables of the system;
•
It manages alarms;
•
It manages the RF status (e.g. on, off…);
•
It manages the mode switch;
•
It manages the ARP resolution in DVB mode.
3
WD_TCP_IP_TASK This task implements the TCP-IP protocol stack. 4
WD_TIMER_TICK_TASK This task generates the clock for the TCP-IP task. 5
WD_STV0371_TASK
This task gathers information from the demodulator
and configures it.
6
The default tasks mask at the board startup is set to 0x0000007D (nb the UPCV task is excepted).
Once the presence of the upconverter is assured, the upconverter task bit is automatically enabled
and the mask is set to 0x0000007F. Tasks execution is stopped during de-fragmentation operations
and FPGA boots.
TSK ERR 00000028, 0000003c