
XRT84L38
378
OCTAL T1/E1/J1 FRAMER
REV. 1.0.1
The table below shows configurations of the Signaling Change Registers.
By reading contents of the Signaling Update status bits of the Framer Interrupt Status Register and the
Signaling Change Registers, the user can clearly identify which one(s) of the thirty-two DS0 channels has
changed signaling information over the last multi-frame period.
Depending on configurations of the XRT84L38 framer, the signaling bits can be extracted from the incoming E1
frame and direct to all or any one of the following destinations:
Signaling data is stored to Receive Signaling Register Array (RSRA) of each channel
Signaling data is sent to the Terminal Equipment through the Receive Signaling Output pin (RxSig_n)
Signaling data is sent to the Terminal Equipment through the Receive Overhead Output pin (RxOH_n)
Signaling data is embedded into the output PCM data sending towards the Terminal Equipment through the
Receive Serial Output pin (RxSer_n)
The follow sections discuss how to configure the XRT84L38 framer to extract signaling information bits and
send them to different destinations.
12.4.1.1
Store Signaling Bits into RSRA Register Array
The four least significant bits of the Receive Signaling Register Array (RSRA) of each timeslot can be used to
store received signaling data. The user can read these bits through microprocessor access. If the XRT84L38
framer is configure to extract signaling bits from incoming E1 payload data, the E1 Receive Framer block will
strip off the CAS signaling bits from time slot 16 of the incoming E1 frames and store them into appropriate
locations of the RSRA. The extraction of signaling bit from E1 PCM data is done on a per-channel basis. The
Bit 3 of RSRA register is used to hole Signaling bit A. Bit 2 is used to hold Signaling bit B. Bit 1 is used to hold
Signaling bit C. Bit 0 is used to hold Signaling bit D.
The table below shows the four least significant bits of the Receive Signaling Register Array.
12.4.1.2
Outputting Signaling Bits through RxSig_n Pin
The XRT84L38 framer can be configure to output extracted signaling bits to external equipment through the
RxSig_n pins. This pin is a multiplexed I/O pin with two functions:
RxTSb[0]_n - Receive Timeslot Number Bit [0] Output pin
SIGNALING CHANGE REGISTERS (SCR) (INDIRECT ADDRESS = 0XN0H, 0X0DH - 0X10H)
L
OCATION
\ B
IT
B
IT
7
B
IT
6
B
IT
5
B
IT
4
B
IT
3
B
IT
2
B
IT
1
B
IT
0
0xn0H - 0x0DH
Ch 0
Ch 1
Ch 2
Ch 3
Ch 4
Ch 5
Ch 6
Ch 7
0xn0H - 0x0EH
Ch 8
Ch 9
Ch 10
Ch 11
Ch 12
Ch 13
Ch 14
Ch 15
0xn0H - 0x0FH
Ch 16
Ch 17
Ch 18
Ch 19
Ch 20
Ch 21
Ch 22
Ch 23
0xn0H - 0x0FH
Ch 24
Ch 25
Ch 26
Ch 27
Ch 28
Ch 29
Ch 30
Ch 31
RECEIVE SIGNALING REGISTER ARRAY (RSRA) (INDIRECT ADDRESS = 0XN4H, 0X00H - 0X1FH)
B
IT
N
UMBER
B
IT
N
AME
B
IT
T
YPE
B
IT
D
ESCRIPTION
3
Signaling Bit A
R/W
This bit is used to store Signaling Bit A that is received and extracted.
2
Signaling Bit B
R/W
This bit is used to store Signaling Bit B that is received and extracted.
1
Signaling Bit C
R/W
This bit is used to store Signaling Bit C that is received and extracted.
0
Signaling Bit D
R/W
This bit is used to store Signaling Bit D that is received and extracted.