TMXF28155 Supermapper
155/51 Mbits/s SONET/SDH x28/x21 DS1/E1
Data Sheet
June 2002
472
Agere Systems Inc.
20 M13/M23 MUX/DeMUX Block Functional Description
(continued)
Table 587. C-Bit Parity Description and Transmit Value
20.7.6 FEAC
The third C bit of each DS3 frame provides a far-end alarm and control (FEAC) signal. The use of this signal and
FEAC code words are defined in T1.107 and GR-499-CORE.
When the FEAC signal is not active, it is transmitted continuously as a 1. The user can provision the M13 to trans-
mit continuous ones by setting M13_TFEAC_CTL[1:0] to 00 (
Table 290 on page 224
).
Active FEAC signals consist of repeating 16-bit code words of the form 0 x5x4x3x2x1x0 0 11111111, where xi can
be a 1 or a 0. The code words are transmitted right to left one bit each DS3 frame for 16 consecutive frames.
Alarm and Status Signals.
EAC alarm and status signals should be transmitted continuously for the duration of
the condition being reported, or for a minimum of 10 repetitions of the code word. FEAC signals are transmitted
continuously by setting M13_TFEAC_CTL[1:0] to 01, and M13_TFEAC_CODE[5:0] to x5x4x3x2x1x0 (
Table 290
),
where x5x4x3x2x1x0 is the appropriate value for the alarm or status code word.
Control Signals.
EAC control signals are defined for activating or deactivating a loopback. Code words for loop-
back activation, deactivation, and specifying the type of loopback can be transmitted using the same method as
described above for alarm and status signals. Alternatively, the user may provision the M13 to automatically send
the activate or deactivate commands.
In order to activate a loopback, the user may set M13_TFEAC_CTL[1:0] to 11, and M13_TFEAC_CODE[5:0] to
x5x4x3x2x1x0, where x5x4x3x2x1x0 is the appropriate value for the loopback code word. The M13 will then trans-
mit 10 repetitions of the activate code word, 0 000111 0 11111111 followed by 10 repetitions of
0x5x4x3x2x1x0 0 11111111. After transmitting this 40 octet sequence, it will set M13_TFEAC_DONE to 1
(
Table 229 on page 204
).
In order to deactivate a loopback, the user may set M13_TFEAC_CTL[1:0] to 10, and M13_TFEAC_CODE[5:0] to
x5x4x3x2x1x0, where x5x4x3x2x1x0 is the appropriate value for the loopback code word. The M13 will then trans-
mit 10 repetitions of the deactivate code word, 0 011100 0 11111111, followed by 10 repetitions of
0x5x4x3x2x1x0 0 11111111. After transmitting this 40 octet sequence, it will set M13_TFEAC_DONE to 1.
C Bit Number
C1
C2
Description
C-Bit Parity Identification
Network Requirements Bit
Transmit Value
1.
If M13_CBIT2_ACT = 0 (
Table 289 on page 224
), the C2 bit
is set to 1.
If M13_CBIT2_ACT = 1, the transmit value of C2 is input
through pin TCBDATA (E12).
C3
Far-End Alarm and Control (FEAC) See FEAC below.
Unused
C4—C6,
C16—C21
If M13_UNUSED_ACT = 0 (
Table 289
), all are transmitted
as 1.
If M13_UNUSED_ACT = 1, the transmit values are input
through pin TCBDATA (E12).
Set to the same value as the P bits.
See
Section 20.7.7 on page 473
.
See
Section 20.7.8 on page 473
.
C7—C9
C10—C12
C13—C15
CP Bits (path DS3 parity)
Far-End Block Error (FEBE) Bits
Terminal-to-Terminal Data Link