Rainbow Electronics DS2151Q - Manual (Page 2)

DS2151Q
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or 128 bits) can be placed in either the transmit or
receive data paths. The framer locates the frame and
multiframe boundaries and monitors the data stream for
alarms. It is also used for extracting and inserting
Robbed–Bit signaling data and FDL data. The device
contains a set of 64 eight bit internal registers which the
user can access and control the operation of the unit.
Quick access via the parallel control port allows a single
micro to handle many T1 lines. The device fully meets
all of the latest T1 specifications including ANSI
T1.403–199X, AT&T TR 62411 (12–90), and ITU G.703,
G.704, G.706, G.823, and I.431.
TABLE OF CONTENTS
1. Introduction
2. Parallel Control Port
3. Control Registers
4. Status and Information Registers
5. Error Count Registers
6. FDL/Fs Extraction/Insertion
7. Signaling Operation
8. Transmit Transparency and Idle Registers
9. Clock Blocking Registers
10. Elastic Stores Operation
11. Receive Mark Registers
12. Line Interface Functions
13. Timing Diagrams and Transmit Flow Diagram
14. DC and AC Characteristics
1.0 INTRODUCTION
The analog AMI waveform off of the T1 line is trans-
former coupled into the RRING and RTIP pins of the
DS2151Q. The device recovers clock and data from the
analog signal and passes it through the jitter attenuation
mux to the receive side framer where the digital serial
stream is analyzed to locate the framing pattern. If
needed, the receive side elastic store can be enabled in
order to absorb the phase and frequency differences
between the recovered T1 data stream and an asynch-
ronous backplane clock which is provided at the
SYSCLK input.
The transmit side of the DS2151Q is totally independent
from the receive side in both the clock requirements and
characteristics. Data can be either provided directly to
the transmit formatter or via an elastic store. The trans-
mit formatter will provide the necessary data overhead
for T1 transmission. Once the data stream has been
prepared for transmission, it is sent via the jitter attenua-
tion mux to the waveshaping and line driver functions.
The DS2151Q will drive the T1 line from the TTIP and
TRING pins via a coupling transformer.