stlc3040 STMicroelectronics, stlc3040 Datasheet - Page 27

• Manufacturer Part Number: stlc3040
• Description: Subscriber Line Interface Codec Filter, Cofislic
• Manufacturer: STMicroelectronics

6.1.4. TEST MODE 4 (TST-800Hz)
The device is in Active mode. An 800Hz tone is
injected into the line. The tone amplitude is pro-
grammable through TTX voltage register (CR10).
1KHz tone can be added (CR1.4), in this case Rx
input is disabled.
6.1.5. TEST MODE 5 (TST-TONE-CAL)
It carries out a tone calibration.
1KHz frequency is sent to backplane (TX direc-
tion)
Returned Information on Tx B1 byte:
6.1.6. TEST MODE 7 (TST-ALB)
A 1KHz Tone can be generated in digital section.
This Test mode is equivalent to the Active mode.
Disabling B filter, the gain of the whole path (Rx +
HV (L3000N, L3000S, STLC3170) + external load
+ Tx) can be measured.
The measurement is carried out by a window de-
tector placed at the input of the PCM encoder.
The window detector compares the negative or
positive amplitude peak (it depends on the pro-
grammed battery polarity) of the input signal with
a range of values.
The range is centred around 6dB below the PCM
full scale. Range width is 0.5dB or 1.5dB de-
pending on the programmed polarity.
Returned information on upstream GCI channel:
CR2.6 = 1 means signal level within the window
range.
Operating Mode:
B filter:
Z Synthesis:
Rx Path:
Tx Path:
R, GR Filters:
DC Synthesis:
TTX:
Internal Tone
Generation in Rx:
I
Hook Detection:
High Pass Filters:
LIM
1.
2. CR2.6 (OKTON)
3. CR2.7 (XVA) = 1means measurement has
1KHz Tone at the maximum digital level
:
settled
50
I
t
R
AC
Tx
GAIN
Active
Programmable
Programmable
Functional
Off
Gain as per programmed
coefficients
On
Functional
1KHz available
On
As in Active
Controlled by CR1.1 and
CR11.1
When this Test mode is on, all the functionalities
of Active mode are still available. In addition the
window detector is switched on.
6.1.7. TEST MODE 9 (TST-LINE-IMPDC)
In this mode thr Rx channel is functional and its
gain is increased by a factor 16 (the same gain is
also applied to the 1KHz enabled by CR1.4).
Z, ILIM and DC feed characteristics are disabled.
A drop of roughly 3.9V/step is superimposed to
the line under control of CR10 [7:3].
Tx path is fully functional and controllable. Trans-
versal line current (I
allel R
6.1.8. TEST MODE A (TST-LINE-IMPAC)
This test follows the same procedure as Test 9
having the sensing done only on R
Measured value:
6.1.9. TEST MODE C (TST-IRING)
Normal Ring signal (no power reduced mode
available) is generated and sent to 2-wire in order
to test internal ring generator. Frequency and Am-
plitude are programmable by CR5 register.
Auto Ring Trip function can be disabled by R
Operating Mode:
B Filter:
Z Filter:
Rx Path:
Tx Path:
R, X, GR, Gx:
KD:
DC Synthesis:
TTX:
Internal Tone
Generation in Rx:
Hook detection:
I
High Pass Filters
Reverse Polarity
LIM
Modulated if TMM = 1 in CR8 register.
50
50
I
i
t
t
DC
Tx GAIN
Tx GAIN
, C
AC
:
R
R
6
DC
6
DC
t
) is measured across the par-
Test Dedicated, H.V. set by
downstream C/I
Programmable
Off
Functional
Functional
Programmable
Programmable (Suggested
max. value to avoid
saturation = 800h)
Only Programmable Voltage
drop
Not Applicable
1KHz available
As in active mode
As per programmed value in
Active mode
Controlled by CR1.1 and
CR11.1
Set by SOP register
command
C
AC
DC
.
STLC3040
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TEN