
XRT84L38
247
REV. 1.0.1
OCTAL T1/E1/J1 FRAMER
6.0
THE E1 TRANSMIT SECTION
6.1
The E1 Transmit Payload Data Input Interface Block
6.1.1
Description of the Transmit Payload Data Input Interface Block
Each of the eight framers within the XRT84L38 device includes a Transmit Payload Data Input Interface block.
The function of this block is to provide an interface to the local Terminal Equipment (for example, a Central
Office or switching equipment) that has data to send to a "Far End" terminal over a DS1 or E1 transport
medium.
The Payload Data Input Interface module (also known as the Back-plane Interface module) supports payload
data to be taken from or presented to the system. In DS1 mode, supported data rates are 1.544Mbit/s, MVIP
2.048Mbit/s, 4.096Mbit/s, 8.192Mbit/s, multiplexed 12.352Mbit/s, multiplexed 16.384Mbit/s, HMVIP
16.384Mbit/s or H.100 16.384Mbit/s. In E1 mode, supported data rates are XRT84V24 compatible 2.048Mbit/s,
MVIP 2.048Mbit/s, 4.096Mbit/s, 8.192Mbit/s, multiplexed 16.384Mbit/s, HMVIP 16.384Mbit/s or H.100
16.384Mbit/s.
The Transmit Payload Data Input Interface block supplies or accepts the following signals to the local Terminal
Equipment circuitry:
Transmit Serial Data Input (TxSer_n)
Transmit Serial Clock (TxSerClk_n)
Transmit Single-frame Synchronization Signal (TxSync_n)
Transmit Multi-frame Synchronization Signal (TxMSync_n)
Transmit Time-slot Indicator Clock (TxTSClk_n)
Transmit Time-slot Indication Bits (TxTSb[4:0]_n)
The Transmit Serial Data is an input pin carrying payload, signaling and sometimes Data Link data supplied by
the local Terminal Equipment to the XRT84L38 device.
The Transmit Serial Clock is an input or output signal used by the Transmit Payload Data Input Interface block
to latch in incoming serial data from the local Terminal Equipment. The Transmit Clock Inversion bit of the
Transmit Interface Control Register (TICR) determines at which edge of the Transmit Serial Clock would data
transition on the Transmit Serial Data pin occur.
The table below shows configurations of the Transmit Clock Inversion bit of the Transmit Interface Control
Register (TICR).
TRANSMIT INTERFACE CONTROL REGISTER (TICR) (INDIRECT ADDRESS = 0XN0H, 0X20H)
Throughout the discussion of this datasheet, we assume that serial data transition happens on rising edge of
the Transmit Serial Clock unless stated otherwise.
The Transmit Single-frame Synchronization signal is either input or output. When configured as input, it
indicates the beginning of an E1 frame. When configured as output, it indicates the end of an E1 frame.
The Transmit Multi-frame Synchronization signal is either input or output. When configured as input, it indicates
the beginning of an E1 multi-frame. When configure as output, it indicates the end of an E1 multi-frame.
The Transmit Input Clock signal is multiplexed into the Transmit Multi-frame Synchronization pin (TxMSync_n)
of the XRT84L38. When the framer is running at High-speed Back-plane Interface mode, the Transmit Input
Clock functions as the timing source for the High-speed Back-plane Interface.
B
IT
N
UMBER
B
IT
N
AME
B
IT
T
YPE
B
IT
D
ESCRIPTION
3
Transmit Clock
Inversion
R/W
0 - Serial data transition happens on rising edge of the Transmit Serial Clock.
1 - Serial data transition happens on falling edge of the Transmit Serial Clock.