BT8375 CONEXANT [Conexant Systems, Inc], BT8375 Datasheet - Page 195

• Manufacturer Part Number: BT8375
• Description: single chip transceivers for T1/E1 and Integrated Service Digital Network (ISDN) primary rate interfaces
• Manufacturer: CONEXANT [Conexant Systems, Inc]

Bt8370/8375/8376
Fully Integrated T1/E1 Framer and Line Interface
AUTO_AIS /TAIS
TPSTART
FRAMED
ZLIMIT
N8370DSE
076—Transmit Test Pattern Configuration (TPATT)
—
7
Automatic Manual Transmit Alarm Indication Signal—When activated manually (TAIS) or
automatically (AUTO_AIS), the alarm formatter replaces all data output on TPOSO/TNEGO
and XTIP/XRING with an unframed all-1s signal (AIS). This includes replacing data supplied
from TPOSI/TNEGI and from the receiver during line loopback [LLOOP; addr 014].
Automatic mode sends AIS for the duration of receive loss of signal [RLOS; addr 047] or
receive loss of clock [RLOC; addr 047], depending on the analog or digital line interface
option [RDIGI; addr 020]. If AISCLK [addr 068] is enabled, TAIS also provides manual
switch control over ACKI clock input. AUTO_AIS does not affect ACKI switching.
transmit data that is looped back to the receiver during framer loopback [FLOOP; addr 014].
This allows both FLOOP and LLOOP to be active simultaneously during loss of signal,
without disrupting data in the framer loopback path.
Enable Test Pattern Transmission.
PRBS Framed—When set, the PRBS pattern does not overwrite framing bit positions and is
stopped during these bit periods. In T1 mode, the frame bit (every 193
In E1 mode, the PRBS test pattern is not written to time slot 0 (FAS and NFAS words) and
time slot 16 (CAS signalling word) if CAS framing is also selected. CAS framing is selected
by setting TFRAME[3] to 1 in the Transmit Configuration register [TCR0; addr 070]. If
FRAMED is disabled, the test pattern is transmitted in all time slots.
Enable 0 Limit; 7/14 depending on pattern.
—
AIS transmission [TAIS, AUTO_AIS; addr 075, or AISCLK; addr 068] does not affect
6
NOTE:
TAIS
0
0
0
0
1
1
—
5
Systems that transmit framed all ones can utilize inband loopback code generator
[TLB; addr 077] to send all ones in payload only.
AUTO_AIS
X
X
0
0
1
1
TPSTART
4
Conexant
AISC
LK
0
1
0
1
0
1
FRAMED
3
AIS During TLOC or RLOS
AIS During RLOS/RLOC
Manual AIS and ACKI
AIS during TLOC
Normal, No AIS
Transmit Data
Manual AIS
ZLIMIT
2
rd
TPATT[1]
3.12 Transmitter Registers
bit) is not overwritten.
1
ACKI while TLOC
ACKI while TLOC
Transmit Clock
(TCKO)
TCKI
TCKI
TCKI
ACKI
TPATT[0]
0
3-77