tmxf28155 ETC-unknow, tmxf28155 Datasheet - Page 468

• Manufacturer Part Number: tmxf28155
• Description: Tmxf28155 Super Mapper 155/51 Mbits/s Sonet/sdh X28/x21 Ds1/e1
• Manufacturer: ETC-unknow

155/51 Mbits/s SONET/SDH x28/x21 DS1/E1
20 M13/M23 MUX/DeMUX Block Functional Description
For each input data bit that is a 0, the encoder outputs zeros on both its positive and negative outputs, unless doing
so would cause three consecutive output periods of positive and negative zeros. In the latter case, the three con-
secutive input zeros are output as either [00V] or [B0V], where B is a pulse on either the positive or negative output
that is opposite in polarity to the last non-zero output, and V is a pulse that is the same polarity as the last nonzero
output. The choice of [00V] or [B0V] is made so that the polarity of consecutive V-pulses alternates (which is equiv-
alent to forcing the number of B-pulses between successive V-pulses to be odd).
When M13_BIPOLAR = 1, the user can force errors in the bipolar coding by setting M13_BIPOL_ERR
to 1. When this is done, the M13 transmits the next 1 as a bipolar violation.
20.10 DS3 R-to-T Loopback
The received DS3 signal can be looped directly back to the transmit DS3 output. If either M13_LOOP_R_TO_T = 1
(Table
20.7.6 FEAC on page
SMPR_RDS3NEG_BPV input signals are looped to the M13_DS3POS_DATA and M13_DS3NEG outputs, respec-
tively.)
20.10.1 DS3 Transmit Path Interface
When cross connected to the DS3 device pins, the DS3 data out DS3POSDATAOUT (pin R22) and
DS3NEGDATAOUT (pin P22) is clocked out on the falling edge of DS3DATAOUTCLK (pin N22).
If the M13 DS3 interface is optioned for loop timing (M13_LOOP_TIME = 1), the DS3 data is clocked out on the ris-
ing edge of DS3DATAINCLK (pin J22).
20.11 M13/M23 Demultiplexer
20.11.1 DS3 LOC and LOS
SMPR_RDS3CLK is monitored for loss of clock, which is reported through bit M13_RDS3_LOC
user can configure which edge of SMPR_RDS3CLK retimes the data (M13_RDS3_EDGE = 1 (
the rising edge; M13_RDS3_EDGE = 0 selects the falling edge).
The receive DS3 signal is also checked for loss of signal (LOS), which is reported through bit M13_RDS3_LOS
(Table
pulses of either positive or negative polarity at the DS3 input. An LOS defect is terminated upon detecting an aver-
age pulse density of at least 33% over a period of 175 ±75 contiguous pulse positions starting with the receipt of a
pulse. An LOS defect will not be terminated if, at the end of the pulse-position interval, any subintervals of 100
pulse positions containing no pulses of either polarity were observed (T1.231).
B3ZS Decoder.
(SMPR_RDS3CLK and SMPR_RDS3POS_DATA when M13_BIPOLAR = 0
clock, positive data, and negative data (SMPR_RDS3CLK, SMPR_RDS3POS_DATA, and SMPR_RDS3NEG_BPV
when M13_BIPOLAR = 1 and M13_BPV_IN = 0
(external input) (SMPR_RDS3CLK, SMPR_RDS3POS_DATA, and SMPR_RDS3NEG_BPV when
M13_BIPOLAR = 0 and M13_BPV_IN = 1). When M13_BIPOLAR = 0, the received DS3 data and clock are
passed directly to the M23 demultiplexer. When M13_BIPOLAR = 0 and M13_BPV_IN = 1, the received DS3 data
and clock are passed to the M23 demultiplexer while the bipolar violation indication is forwarded to the internal BPV
counter for performance monitoring (B3ZS decoder is not used). When M13_BIPOLAR = 1 and M13_BPV_IN = 0,
the received SMPR_RDS3POS_DATA and SMPR_RDS3NEG_BPV data inputs are first B3ZS decoded.
468
260), or both M13_AUTO_FLB = 1
225). An LOS defect, according to T1.231, is the occurrence of 175 ±75 contiguous pulse positions with no
The receive DS3 device input can either be in the form of unipolar clock and data
465), the loopback is activated. (During loopback, the SMPR_RDS3POS_DATA and
(Table
(Table
259) and M13_DS3_FLB_DET = 1
259)) or unipolar clock, data, and bipolar violation indication
(Table 260 on pag
(continued)
(Table
251) (see
Table
e216)) or unipolar
Agere Systems Inc.
(Table
Section
287) selects
May 2001
(Table
225). The
258)