
IDT82P2284
QUAD T1/E1/J1 LONG HAUL / SHORT HAUL TRANSCEIVER
Functional Description
82
February 25, 2008
Figure 26. E1 To T1/J1 Format Mapping - One Filler Every Fourth Channel Mode
Figure 27. E1 To T1/J1 Format Mapping - Continuous Channels Mode
In the Transmit Clock Slave mode, the timing signal on the TSCKn
pin and the framing pulse on the TSFSn pin to input the data on the
TSDn pin are provided by the system side. When the TSLVCK bit is set
to ‘0’, each link uses its own TSCKn and TSFSn; when the TSLVCK bit
is set to ‘1’ and all four links are in the Transmit Clock Slave mode, the
four links use the TSCK[1] and TSFS[1] to input the data. The signaling
bits on the TSIGn pin are per-channel aligned with the data on the TSDn
pin.
In the Transmit Clock Slave mode, the data on the system interface
is clocked by the TSCKn. The active edge of the TSCKn used to sample
the pulse on the TSFSn is determined by the FE bit. The active edge of
the TSCKn used to sample the data on the TSDn and TSIGn is deter-
mined by the DE bit. If the FE bit and the DE bit are not equal, the pulse
on the TSFSn is ahead. The data rate of the system side is 1.544 Mb/s
or 2.048 Mb/s. When it is 2.048 Mb/s, the TSCKn can be selected by the
CMS bit to be the same rate as the data rate on the system side (2.048
MHz) or double the data rate (4.096 MHz). If all four links use the
TSCK[1] and TSFS[1] to input the data, the CMS bit of the four links
should be set to the same value. If the speed of the TSCKn is double the
data rate, there will be two active edges in one bit duration. In this case,
the EDGE bit determines the active edge to sample the data on the
TSDn and TSIGn pins. The pulse on the TSFSn pin is always sampled
on its first active edge.
In the Transmit Clock Slave mode, the TSFSn can indicate each F-bit
or the first F-bit of every SF/ESF/T1 DM/SLC-96 multi-frame. The indica-
tions are selected by the FSTYP bit. The active polarity of the TSFSn is
selected by the FSINV bit. If the pulse on the TSFSn pin is not an integer
multiple of 125
s, this detection will be indicated by the TCOFAI bit. If
the TCOFAE bit is enabled, an interrupt will be reported by the INT pin
when the TCOFAI bit is ‘1’.
3.18.1.3 Transmit Multiplexed Mode
In the Transmit Multiplexed mode, since the demultiplexed data rate
on the system side (2.048 Mb/s) should be mapped to the data rate in
the line side (1.544 Mb/s), 3 kinds of schemes should be selected by the
MAP[1:0] bits. The schemes per G.802, per One Filler Every Four CHs
and per Continuous CHs are the same as the description in
In the Transmit Multiplexed mode, one multiplexed bus is used to
transmit the data to all four links. The data of Link 1 to Link 4 is byte-
interleaved input from the multiplexed bus 1. When the data on the
multiplexed bus is input to four links, the sequence of the data is
1.544
Mb/s
2.048
Mb/s
CH1
CH2
CH3
F
CH4
CH5
CH6
CH22 CH23 CH24
CH1
F
CH2
TS0
TS2
TS1
TS4
TS5
TS6
TS7
TS8
TS28 TS29 TS30 TS31
TS1
TS0
the 8th bit
CH7
TS3
TS9
the 8th bit
discarded
1.544
Mb/s
2.048
Mb/s
CH1
CH2
CH3
F
CH23
CH1
CH2
CH24
TS0
TS2
TS1
TS23
TS24
TS0
TS1
TS2
TS24
the 8th bit
CH24
TS3
TS25~TS31
the 8th bit
F
F CH1
discarded