
DIGITAL CLP MODEM WITH ADPCM CODEC
S5T8610
15
PRELIMINARY
SYNCH/BER/JAM Pin
The SYNCH/BER/JAM pin is used for three purposes. The first is to signal the host that the initial synchronization
between the hand set and base set is established. The second, used only with 24kbps ADPCM, is to signal the
host that jamming is detected, with the pin finally showing the bit error rate (BER). The third function is used only
with 16kbps ADPCM operation mode.
ADPCM
24kbps
16kbps
First Pulse
Initial Synchronization
Initial Synchronization
Rest of Pulses
Jamming Detection
Bit Error Rate
After receiving the encryption ID from the host, the hand set and the base set modems exchange protocols to
establish initial synchronization between them. Immediately after the initial synchronization, the
SYNCH/BER/JAM pin produces high for 10msec. The pin normally produces low. Therefore, the first output of
the SYNCH/BER/JAM pin is always the high signal for 10msec, representing the initial synchronization.
While the 16kbps ADPCM is running, S5T8610 can detect error and indicate the BER through the
SYNCH/BER/JAM pin. When an error is detected, the pin is set high for a given time duration. The duration of
the high signal represents the BER range. After producing high, the pin produces low for 20msec before detecting
the next BER. The following table shows BER ranges with their assigned pulse duration. For BER lower than 1.99
×
10-8, the pin does not produce high since the error is insignificant.
BER
Symbol Error Rate
Time Between Error
Pulse
Duration
From
above 4.16
×
10-2
4.16
×
10-2
2.08
×
10-2
1.04
×
10-2
5.21
×
10-3
2.60
×
10-3
1.30
×
10-3
6.51
×
10-4
3.26
×
10-4
1.63
×
10-4
8.14
×
10-5
4.07
×
10-5
2.03
×
10-5
1.02
×
10-5
5.09
×
10-6
2.54
×
10-6
1.27
×
10-6
To
From
To
From
To
Above 2-3
below 1 msec
1 msec
2 msec
4 msec
8 msec
16 msec
32 msec
64 msec
128 msec
256 msec
512 msec
1.024 sec
2.048 sec
4.096 sec
8.192 sec
16.384 sec
32.768 sec
20 msec
40 msec
60 msec
80 msec
100 msec
120 msec
140 msec
160 msec
180 msec
200 msec
220 msec
240 msec
260 msec
280 msec
300 msec
320 msec
340 msec
2.08
×
10-2
1.04
×
10-2
5.21
×
10-3
2.60
×
10-3
1.30
×
10-3
6.51
×
10-4
3.26
×
10-4
1.63
×
10-4
8.14
×
10-5
4.07
×
10-5
2.03
×
10-5
1.02
×
10-5
5.09
×
10-6
2.54
×
10-6
1.27
×
10-6
6.36
×
10-7
2-3
2-4
2-5
2-6
2-7
2-8
2-9
2-10
2-11
2-12
2-13
2-14
2-15
2-16
2-17
2-18
2-4
2-5
2-6
2-7
2-8
2-9
2-10
2-11
2-12
2-13
2-14
2-15
2-16
2-17
2-18
2-19
2 msec
4 msec
8 msec
16 msec
32 msec
64 msec
128 msec
256 msec
512 msec
1.024 sec
2.048 sec
4.096 sec
8.192 sec
16.384 sec
32.768 sec
1 min 5.5 sec