am79c02 Advanced Micro Devices, am79c02 Datasheet - Page 46
![no-image](/images/manufacturer_photos/0/0/14/advanced_micro_devices_sml.jpg)
am79c02
Manufacturer Part Number
am79c02
Description
Dual Subscriber Line Audio Processing Circuit Dslac Devices
Manufacturer
Advanced Micro Devices
Datasheet
1.AM79C02.pdf
(48 pages)
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
am79c02AJC
Manufacturer:
ST
Quantity:
4 600
Company:
Part Number:
am79c02AJC
Manufacturer:
AMD
Quantity:
5 510
Part Number:
am79c02AJC
Manufacturer:
AMD
Quantity:
20 000
Company:
Part Number:
am79c02JC
Manufacturer:
AMD
Quantity:
2 400
Part Number:
am79c02JC
Manufacturer:
AMD
Quantity:
20 000
APPLICATIONS
The DSLAC device performs a programmable codec/
filter function for two telephone lines. It interfaces to
the telephone lines through either a transformer or an
electronic SLIC, such as the AMD SLIC devices. The
DSLAC device provides latched digital I/O to control
and monitor two SLICs and has a selectable clock out-
put to operate the switched mode regulator in an
Am795XX family SLIC. When several line conditions
must be matched, a single SLIC design can be used.
The line characteristics (such as apparent impedance,
attenuation, and hybrid balance) can be modified by
programming each DSLAC channel’s coefficients to
meet desired performance. The DSLAC device can
drive a transformer SLIC device without a buffer.
Connection to a PCM highway backplane is implement-
ed by means of a simple buffer chip. Several DSLAC
devices can be bused together into one bus interface
buffer. An intelligent bus interface chip is not required
because each DSLAC device provides its own buffer
control. The DSLAC device can be controlled through
the Microprocessor Interface, either by a microproces-
sor on the linecard or by a central processor.
Controlling the SLIC
SLIC Chopper Clock
The CHCLK output pin on the DSLAC device drives the
CHCLK inputs for AMD switcher type SLICs. The
CHCLK output is a 256 kHz or 293 kHz, TTL compatible
signal that can drive two SLICs. It is active only when
one or both channels are activated; otherwise, it is held
high internally.
SLIC Input/Output
The Am79C02(A) and Am79C031(A) DSLAC device
have five TTL compatible I/O pins (C1 to C5) for each
channel. The Am79C03(A) DSLAC device has only C1
through C4 available. The outputs are programmed us-
ing Command 15 and the status is read back using
Command 16. The direction of the pins (input or output)
is specified by programming the SLIC I/O direction reg-
ister (Command 17). The C5 pins of the Am79C031(A)
are output only and must be programmed as outputs to
be used.
46
Am79C02/03/031(A) Data Sheet
Calculating Coefficients with
WinSLAC Software
The WinSLAC software is a program that models the
DSLAC device, the line conditions, the SLIC, and the
linecard components to obtain the coefficients of the
programmable filters of the DSLAC device and some of
the transmission performance plots.
The following parameters relating to the desired line con-
ditions and the components/circuits used in the linecard
are to be provided as input to the program:
1. Line impedance or the balance impedance of the
2. Desired two-wire impedance that is to appear at the
3. Tabular data for templates describing the frequency
4. Relative analog signal levels for both the transmit
5. Component values and SLIC device selection for
6. Two-wire return loss template is usually specified
7. Four-wire return loss template is usually specified
The output from the WinSLAC program includes the
coefficients of the GR, GX, Z, R, X, B, and EPG filters
as well as transmission performance plots of two-wire
return loss, receive and transmit path frequency re-
sponse, and four-wire return loss.
The software supports the use of the AMD SLICs or
allows entry of a SPICE netlist describing the behavior
of any type of SLIC circuit.
line is specified by the local PTT.
by the local PTT.
linecard terminals of the exchange.
response and attenuation distortion of the design.
and receive two-wire signals.
the analog portion of the line circuits.
by the local PTT.