SI3211 ETC, SI3211 Datasheet - Page 37

• Manufacturer Part Number: SI3211
• Description: PROSLIC PROGRAMMABLE CMOS SLIC/CODEC WITH RINGING/BATTERY VOLTAGE GENERATION
• Manufacturer: ETC

Pulse Metering Generation
There is an additional tone generator suitable for
generating tones above the audio frequency. This
oscillator is provided for the generation of billing tones
which are typically 12 kHz or 16 kHz. The generator
follows the same algorithm as described in "Tone
Generation" on page 30 with the exception that the
sample rate for computation is 64 kHz instead of 8 kHz.
The equations are as follows:
Parameter
Ring Trip Interrupt Pending
Ring Trip Interrupt Enable
Ring Trip Detect Debounce Interval
Ring Trip Threshold
Ring Trip Filter Coefficient
Ring Trip Detect Status (monitor only)
Note: The ProSLIC uses registers that are both directly and indirectly mapped. A “direct” register is one that is mapped
Frequency
Ringing
16.667
Hz
20
30
40
50
60
directly. An “indirect” register is one that is accessed using the indirect access registers (direct registers 28 through
31).
PLSCO
coeff
decimal
=
100
128
213
256
112
=
64
cos
Table 29. Associated Registers for Ring Trip Detection
Table 30. Recommended Ring Trip Values for Ringing
coeff


------------------------- -
64000 Hz
NRTP
2 f
2
15
–


1
06A8
0200
0320
0380
0400
0800
hex
Preliminary Rev. 1.11
decimal
34 mA
34 mA
34 mA
34 mA
34 mA
34 mA
where full scale V
The initial phase of the pulse metering signal is set to 0
internally so there is no register to serve this purpose.
The pulse metering generator timers and associated
pulse metering timer registers are similar to that of the
tone generators. These timers count 8 kHz sample
periods like the other tones even though the sinusoid is
generated at 64 kHz.
NRTP[12:0]
RPTP[5:0]
RPTP
PLSX
RTDI[6:0]
Register
Si3210/Si3211/Si3212
RTIP
RTIE
RTP
=
3600
3600
3600
3600
3600
3600
1
-- - 1 coeff
4
hex
----------------------- -
1
+
–
RMS
coeff
= 0.85 V
2
15.4 ms
12.3 ms
8.96 ms
decimal
15
7.5 ms
4.8 ms
Indirect Register 29
Indirect Register 36
5 ms
Direct Register 19
Direct Register 22
Direct Register 70
Direct Register 68
–
RMS
1
Location
----------------------------------------------
Full Scale V
for a matched load.
Desired V
RTDI
hex
RMS
0F
0B
09
07
05
05
RMS
37