Bt8370/8375/8376
3.8 Receiver Registers
Fully Integrated T1/E1 Framer and Line Interface
042—Receive Loopback Code Detector Configuration (RLB)
7
6
5
4
3
2
1
0
—
—
—
—
DN_LEN[1]
DN_LEN[0]
UP_LEN[1]
UP_LEN[0]
DN_LEN[1:0]
Loopback Deactivate Code Length—Selects the number of loopback pattern bits from LBD
[addr 044] that are compared to received data to determine it a Loopback Deactivate Code
[LOOPDN; addr 048] is detected. LOOPDN is recovered if the received data pattern contains
fewer than 63 bit errors in a 24 ms period. LOOPDN is lost if 64 or more bit errors are detected
in a subsequent 24 ms period. F-bits that overwrite or are inserted into the loopback pattern are
not counted as bit errors. Accurate code detection is provided on lines with up to 1E-3 BER.
DN_LEN
LBD Length
4 Bits
00
01
10
11
5 Bits
6 Bits
7 Bits
UP_LEN[1:0]
Loopback Activate Code Length—Selects the number of loopback pattern bits from LBA
[addr 043] that are compared with received data to determine if a Loopback Activate Code
[LOOPUP; addr 048] is detected. LOOPUP is recovered if received data pattern contains
fewer than 63 bit errors in a 24 ms period. LOOPUP is lost if 64 or more bit errors are detected
in a subsequent 24 ms period. F-bits that overwrite or are inserted into the loopback pattern are
not counted as bit errors. Accurate code detection is provided on lines with up to 1E-3 BER.
UP_LEN
LBA Length
4 Bits
00
01
10
11
5 Bits
6 Bits
7 Bits
043—Loopback Activate Code Pattern (LBA)
7
6
5
4
3
2
1
0
LBA[1]
LBA[2]
LBA[3]
LBA[4]
LBA[5]
LBA[6]
LBA[7]
—
LBA[1]
First bit expected of LOOPUP pattern
Second bit expected of LOOPUP pattern
Third bit expected of LOOPUP pattern
LBA[2]
LBA[3]
LBA[4]
LBA[5]
LBA[6]
LBA[7]
Fourth bit expected—Last bit if UP_LEN selects a 4-bit pattern.
Fifth bit expected—Last bit if UP_LEN selects a 5-bit pattern.
Sixth bit expected—Last bit if UP_LEN selects a 6-bit pattern.
Seventh bit expected—Last bit if UP_LEN selects a 7-bit pattern.
3-50
Conexant
N8370DSE
CONEXANT [ CONEXANT SYSTEMS, INC ]
