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XRT86VL30
18
REV. 1.0.1
SINGLE T1/E1/J1 FRAMER/LIU COMBO - T1 REGISTER DESCRIPTION
5-4
YEL[1:0]
R/W
00
(Continued)
TABLE 6: ALARM GENERATION REGISTER (AGR)
HEX ADDRESS: 0X0108
BIT
FUNCTION
TYPE DEFAULT
DESCRIPTION-OPERATION
TABLE 8: YELLOW ALARM FORMAT WHEN ONE SECOND RULE IS ENFORCED
YEL[1:0]
YELLOW ALARM FORMAT
00
Disable the transmission of yellow alarm
01
SF or N mode:
RAI is transmitted as bit 2 = 0 (second MSB) in all DS0 data channel.
T1DM mode:
RAI is transmitted as Y-bit = 0 (6th bit in the SYNC byte).
ESF mode:
YEL[1:0] controls the format of RAI. When YEL[1:0] is set to’01’, RAI
is transmitted as 255 patterns of 1111_1111_0000_0000 on the 4-
kbit/s data link (M1-M12) (approximately 1 second).
ALARM_ENB (Bit 6 of this register) controls the duration of RAI as
described below:
1. If ALARM_ENB bit is set ’high’ for a duration shorter or equal
to
the
time
required
to
transmit
255
pattern
of
1111_1111_0000_0000 on the 4-kbit/s data link (M1-M12), RAI
is transmitted for 255 patterns. (approximately 1 second)
2. If ALARM_ENB bit is set ’high’ for a duration longer than the
time
required
to
transmit
255
patterns
of
1111_1111_0000_0000 on the 4-kbit/s data link (M1-M12), RAI
continues until ALARM_ENB bit is set ’low’.
3. If ALARM_ENB forms another pulse during an alarm
transmission, it resets the pattern counter and extends the
RAI duration for another 255 patterns.(approximately 1
second)
NOTE: A minimum of one second delay between termination of the
first RAI and the initiation of a subsequent RAI is enforced.
10
SF mode:
RAI is transmitted as a “1” in the Fs bit of frame 12 (This is RAI for J1
SF standard).
T1DM mode:
RAI is transmitted as Y-bit = 0 (6th bit in the SYNC byte).
ESF mode:
RAI is controlled by the duration of ALARM_ENB bit. This allows
continuous RAI of any length.
11
SF, N, and T1DM mode:
RAI format is the same as described above when YEL[1:0] is set
to’01’.
ESF mode:
RAI duration is the same as described above when YEL[1:0] is set
to’01’, except that format of RAI is transmitted as 255 patterns of
1111_1111_1111_1111 on the 4kbits/s data link bits (J1 ESF stan-
dard) instead of 255 patterns of 1111_1111_0000_0000.