TP3420A ISDN S/T Interface Device
General Description
The TP3420A is an enhanced version of the TP3420, with a
number of upgraded features for compliance with the new
release of ANSI T1.605-1991 and CCITT I-430. At initial
power-up the device is fully backwards compatible with the
TP3420 device, and modifications to the firmware are only
required to take advantage of the new features.
The TP3420A S Interface Device (SID?) is a complete
monolithic transceiver for data transmission on twisted pair
subscriber loops. It is built on National’s advanced 1.0 micron
double-metal CMOS process, and requires only a
single +5V supply. All functions specified in CCITT recommendation
I.430 (1991) and ANSI T1.605 (1991) for ISDN
basic access at the “S” and “T” interfaces are provided, and
the device can be configured to operate either in a TE (Terminal
Equipment), in an NT-1 or NT-2 (Network Termination)
or as a PABX line-card or trunk-card device.
As specified in I.430, full-duplex transmission at 192 kb/s is
provided on separate transmit and receive twisted wire pairs
using inverted Alternate Mark Inversion (AMI) line coding. 2
“B” channels, each of 64 kb/s, and 1 “D” channel at 16 kb/s
are available for users’ data. In addition, the TP3420A provides
the 800 b/s “S1”, “S2” & “Q” multiframe channels for
Layer 1 maintenance.
All I.430 wiring configurations are supported by the TP3420A
SID, including the “passive bus” for up to 8 TE’s distributed
within 200 meters of low capacitance cable, and
point-to-point and point-to-star connections up to at least
1500 meters (24AWG). Adaptive receive signal processing
ensures low bit error rates on any of the standard types of
cable pairs commonly found in premise wiring installations
when tested with the noise sources specified in I.430.
Features
n 2 B + D 4-wire 192 kb/s transceiver
n Selectable TE or NT mode
n Exceeds I.430 range: 1.5 km point-to-point
n Adaptive receiver for high noise immunity
n Adaptive and fixed timing options for NT-1
n Clock resynchronizer and elastic buffers for NT-2/LT
n Slave-slave mode for NT-2 trunks
n Extensive hardware support for SC1, SC2 and Q
channel messaging
n Bipolar violation detection and FECV messaging
n Selectable system interface formats
n MICROWIRE? and SCP compatible serial control
interface
n TP3054/7 Codec/Filter COMBO? compatibility
n Single +5V supply
n 20-pin package DIP, PLCC
Applications
n Same Device for NT, TE and PBX Line Card
n Point-to-Point Range Extended to 1.5 km
n Point-to-Multipoint for all I.430 Configurations
n Easy Interface t
LAPD Processor MC68302, HPC16400
Terminal Adapter MC68302, HPC16400
Codec/Filter COMBO TP3054/7 and TP3076
“U” Interface Device TP3410
Line Card Backplanes—No External PLL Needed
n Line Monitor Mode for Test Equipment