W93910 Datasheet, PDF (18/35 Pages) Winbond – ERMES PAGING DECODER

W93910
DIGITAL FILTER & POWER SAVING
The W93910 provides different digital filter to remove the noise of the 4FSK signal. The enhanced
filtering require higher power consumption. Table 14 shows different combinations of digital filtering and
power saving.
OPTION BIT
FUNCTION
FILT1
LPWR
Digital filter & power saving
0
0
Low power consumption, normal filtering
1
1
Enhanced filtering, high power consumption
Table 14. Digital filter and power saving option
DE-INTERLEAVER AND ERROR CORRECTION
The W93910 performs 2 bits random error correction for system information, address partition as well
as message partition, and codeword de-interleaving for message partition.
TIME OUT CONTROL
When the decoder recognizes a valid initial address it will start to search the associated paging
message. Time out criteria will stop message searching at once. While the searching is stopped due to
time out issue, the "epa" and "etm" in EDW format will be set to indicated the time out situation. At the
mean time, the RF control signal will become inactive at once when ending message delimiter (MD) has
been detected.
• For Individual calls
Two time out criteria shall apply. The earliest detected shall prevail:
1. If PA5−PA0 in paging message is not consistent throughout the receiving, then the epa flag will be
set to "1".
2. If the paging message lasts more than 12 sec, then etm flag will be set to "1".
• For group calls
Individual member shall cease message search if:
1. If PA5−PA0 in paging message is not consistent throughout the receiving, then the epa flag will be
set to "1".
2. If the paging message lasts more than 12 sec, then etm flag will be set to "1".
• For long message calls
The time out criteria for each sub-message is the same as for individual call. The time out of the whole
long message should be proceeded by the software to meet the ERMES protocol.
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