m28333-3x Mindspeed Technologies, m28333-3x Datasheet - Page 36

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

2.0 Functional Description
2.3 Receiver
2.3.7 Data Squelching
2-12
in bold text. A valid bipolar pulse is indicated by a B. A bipolar violation
(non-alternating positive or negative) pulse is indicated by a V .
a bipolar violation as a B. A coding violation or a valid 0 substitution resets the
counter.
are sent out over RPOS (RNRZ) and RNEG (RLCV) pins. These outputs are then
decoded by the Framer or other downstream device. Line code violations are not
detected in this mode of operation. The decoder is configurable for either:
(see
A counter in the receiver keeps track of the number of consecutive symbol
periods without a valid data pulse. When 128 or more 0s in a row are counted, the
receiver assumes that it has lost the signal and resets itself to try and regain the
signal. While the receiver is reacquiring the signal, the clock recovery block locks
to the reference clock and the data squelching is achieved by forcing the data bits
to zero. The data squelching is true in both NRZ and dual rail mode. When the
input signal has been properly amplified and equalized, the clock recovery PLL
will then switch to the incoming data.
The following shows data sequence criteria for LCV; violations are indicated
• Excessive zeros: 0, 0, 0, 0 (HDB3) or 0, 0, 0 (B3ZS). These violations are
• Bipolar violation: B, 0, V (i.e., +1, 0, +1 or -1, 0, -1 for HDB3) B, V
• Coding violation: 0, 0, V (HDB3) or 0, V (B3ZS) with an even number of
The even/odd counter (used to count the number of Bs between Vs) will count
When ENDECDIS = 1, the decoder is disabled, and the retimed slicer outputs
• E3 mode using HDB3 coding (E3MODE = 1)
• DS3/STS-1 mode using B3ZS coding (E3MODE = 0)
The receiver digital data outputs are centered on the rising edge of RCLK
Section
passed on as 0 data on the RNRZ pin.
(B3ZS and HDB3). These violations are passed on as 1 data on the RNRZ
pin.
Bs since the last valid 0 substitution V (follows coding rule). These
violations are passed on as 0 data on the RNRZ pin.
Mindspeed Technologies
2.9).
Single/Dual/Triple E3/DS3/STS-1 Line Interface Unit
™
M28331/M28332/M28333 (–3x)
28333-DSH-003-A