m28333-3x Mindspeed Technologies, m28333-3x Datasheet - Page 33

• Manufacturer Part Number: m28333-3x
• Description: Single/dual/triple E3/ds3/sts-1 Line Interface Unit
• Manufacturer: Mindspeed Technologies

M28331/M28332/M28333 (–3x)
Single/Dual/Triple E3/DS3/STS-1 Line Interface Unit
2.2.5 Transmit Monitor Block
2.2.6 Jitter Generation (Intrinsic)
28333-DSH-003-A
The Transmit (TX) Monitor pins allow the M2833i to monitor for certain fault
condition occurrences such as short circuits or defective channel output drivers in
the device. The TX Monitor inputs (TMONP and TMONM) are independent
functions where TMONP and TMONM must be externally connected (via 0-
resistors or directly) to the TLINEP and TLINEM/N pins.
greater than the threshold of ±0.5 V and to assert a Loss Of Signal (TLOS)
indicator when no output pulse has been detected for 32 TCLK periods. When the
TMONP/TMONM pins are connected, the TX Monitor circuitry only responds to
a voltage difference between the pair, i.e., if TLINEP stops working but
TLINEM/N is still swinging ±1 V, the TX Monitor circuit reports a Not Asserted
status.
detected. TLOS Output pins are active-high when the monitor inputs do not
detect a signal. A special pin (TMONTST) is available for testing board-level
functionality downstream from the TLOS outputs. When TMONTST is high, it
asserts all TLOS channel outputs.
redundancy. This is where the TX monitor of one device is used to monitor a
second active device. When the TMON circuit detects an output driver failure, it
asserts a TLOS, which can now be used to activate the second device’s
transmitter and output disable the primary device.
The M2833i device meets the jitter generation requirements for various rates with
large margins, with the condition that the input transmit clock (TCLK) is
jitter-free. Data rates and jitter generation requirements are defined in the
following documents:
The TX monitors are designed to monitor the line driver outputs for pulses
After a TLOS condition is asserted, it will not deassert until a pulse is again
Other typical TMON circuit applications are for transmitter device
• E3 rate—ETSI TBR24, ITU-T G.823
• DS3 rate—Bellcore GR499, AT&T Accunet TR54014, ITU-T G.824
• STS-1 rate—Bellcore GR253
Mindspeed Technologies
™
2.0 Functional Description
2.2 Transmitter
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