BT8375 CONEXANT [Conexant Systems, Inc], BT8375 Datasheet - Page 128

• 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]

3.0 Registers
3.2 Global Control and Status Registers
RFRAME[3:0]
T1/E1N
3-10
Receiver Framer mode—Establishes the offline framer's search criteria for recovery of frame
alignment (reframe). Also works in conjunction with the RLOFA–RLOFD bits [addr 040] to
establish the online framer's criteria for loss of frame alignment. Refer to
Table A-1, Superframe Format
bits are monitored, and refer to
Alignment
descriptions are listed in
loss/recovery of multiframe alignment is also selected by RFRAME[3:0].
Global T1/E1 Select—Affects all Bt8370/8375/8376 functions by enabling receive and
transmit circuits to operate at either the T1 or E1 line rate. The processor must reinitialize all
control register settings after changing the T1/E1N control bit. T1/E1N selects the nominal
line rate (shown below), while the exact receive and transmit line rate frequencies are
independently determined by their respective input clock or data references. The actual receive
and transmit line frequency can vary within defined tolerances.
for frame alignment loss/recovery criteria during the selected mode. Mode
Table 3-2. Receive Framer Modes
RFRAME[3:0]
000X
001X
010X
011X
100X
101X
110X
111X
0000
0001
0100
0101
0110
1000
1001
1100
1101
0 = 2.048 MHz line rate (E1)
1 = 1.544 MHz line rate (T1)
Table
3-2. The online framer’s SF, SLC, CAS, and MFAS criteria for
Table 2-3, Criteria for Loss/Recovery of Receive Framer
through
Conexant
T1/E1N
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
Table A-1, Superframe Format
Fully Integrated T1/E1 Framer and Line Interface
FAS Only
FAS Only + BSLIP
FAS + CRC
FAS + CRC + BSLIP
FAS + CAS
FAS + CAS + BSLIP
FAS + CRC + CAS
FAS + CRC + CAS + BSLIP
FT Only
ESF + No CRC (FPS only)
SF
SF + JYEL
SF + T1DM
SLC + FSLOF
SLC
ESF + Mimic CRC
ESF + Force CRC
Receive Framer Mode
to find which frame
Bt8370/8375/8376
N8370DSE