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IDT82P2281
SINGLE T1/E1/J1 LONG HAUL / SHORT HAUL TRANSCEIVER
66
October 7, 2003
3.18.2.3
Transmit Multiplexed Mode
In the Transmit Multiplexed mode, one multiplexed bus is used to
transmit the data to the link. The data of the link is byte-interleaved input
from the multiplexed bus. When the data on the multiplexed bus is input
to the link, the position of the data is arranged by setting the timeslot off-
set.
In the Transmit Multiplexed mode, the timing signal on the MTSCK
pin and the framing pulse on the MTSFS pin are provided by the system
side. The signaling bits on the MTSIG pin are per-timeslot aligned with
the corresponding data on the MTSD pin.
In the Transmit Multiplexed mode, the data on the system interface
is clocked by the MTSCK. The active edge of the MTSCK used to sam-
ple the pulse on the MTSFS is determined by the FE bit. The active
edge of the MTSCK used to sample the data on the MTSD and MTSIG
is determined by the DE bit. If the FE bit and the DE bit are not equal,
the pulse on the MTSFS is ahead. The MTSCK can be selected by the
CMS bit to be the same rate as the data rate on the system side (8.192
MHz) or double the data rate (16.384 MHz). If the speed of the MTSCK
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 MTSD and MTSIG pins. The pulse on the MTSFS pin is
always sampled on its first active edge.
In the Transmit Multiplexed mode, the MTSFS can indicate the
Basic frame, CRC Multi-frame and/or Signaling Multi-frame of the first
link. The indications are selected by the FSTYP bit. The active polarity of
the MTSFS is selected by the FSINV bit. If the pulse on the MTSFS pin
is not an integer multiple of 125
μ
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’.
3.18.2.4
Offset
Bit offset and timeslot offset are both supported in all the operating
modes. The offset is between the framing pulse on the TSFS/MTSFS
pin and the start of the corresponding frame input on the TSD/MTSD
pin. The signaling bits on the TSIG/MTSIG pin are always per-timeslot
aligned with the data on the TSD/MTSD pin.
Refer to Chapter 3.18.1.4 Offset for the base line without offset in
different operating modes and the configuration of the offset.
In Non-multiplexed mode, the timeslot offset can be configured
from 0 to 31 timeslots (0 & 31 are included). In Multiplexed mode, the
timeslot offset can be configured from 0 to 127 timeslots (0 & 127 are
included).
Table 44: Related Bit / Register In Chapter 3.18
Bit
Register
Address (Hex)
TMUX
MTSDA
TMODE
MAP[1:0]
(T1/J1 only)
G56K
GAP
PCCE
FBITGAP
(T1/J1 only)
FE
DE
FSTYP
FSINV
CMS
EDGE
BOFF[2:0]
TCOFAI
TCOFAE
TSOFF[6:0]
Note:
*
ID means Indirect Register in the Transmit Payload Control function block.
Backplane Global Configuration
010
TBIF Operating Mode
043
ID * - Channel Control (for T1/J1) /
Timeslot Control (for E1)
TPLC Control Enable
TPLC ID * - 01~18 (for
T1/J1) / 00~1F (for E1)
0CC
TBIF Option Register
042
TBIF Bit Offset
045
RTSFS Change Indication
RTSFS Interrupt Control
TBIF TS Offset
04B
04C
044