DS3112
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8
BERT
The BERT block can generate and detect the following patterns:
Pseudorandom patterns 2
7 - 1, 211 - 1, 215 - 1, and QRSS
A repetitive pattern from 1 to 32 bits in length
Alternating (16-bit) words that flip every 1 to 256 words
The BERT receiver has a 32-bit bit counter and a 24-bit error counter. It can generate interrupts on
detecting a bit error, a change in synchronization, or if an overflow occurs in the bit and error counters.
See Section
8.1 for details on status bits and interrupts from the BERT block. To activate the BERT
block, the host must configure the BERT mux via the BERT mux control register (Section
8.1). Data can
be routed to the receive side of the BERT from either the T3/E3 framer or from one of the 28 T1 or 16/21
E1 receive ports. Data from the transmit side of the BERT can be inserted either into the T3/E3 framer or
into one of the 28 T1 or 16/21 E1 transmit ports. See
Figure 1-1 and
Figure 1-2 for a visual description of
where data to and from the BERT can be placed.
8.1 BERT Register Description
Register Name:
BERTMC
Register Description:
BERT Mux Control Register
Register Address:
0x6Eh
Bit #
7
6
5
4
3
2
1
Name
RBPS3
RBPS2
RBPS1
0
—
RBPS4
RBPS0
Default
0
—
0
Bit #
15
14
13
12
11
10
9
8
Name
—
TBPS4
TBPS3
TBPS2
TBPS1
TBPS0
Default
—
0
Note: Bits that are underlined are read-only; all other bits are read-write.
Bits 0 to 4: Receive BERT Port Select Bits 0 to 4 (RBPS0 to RBPS4). These bits determine if data from any of
the 28 T1 or 16/21 E1 receive ports or the T3/E3 receive framer (with or without the overhead bits) will be routed
to the receive side of the BERT. If these bits are set to 11101, only the T3/E3 payload data will be routed to the
receive BERT. If these bits are set to 11110, all T3/E3 data (payload and the overhead bits) will be routed to the
receive BERT.
RBPS4:0
00000
No Data
01000
Port 8
00001
Port 1
01001
Port 9
00010
Port 2
01010
Port 10
00011
Port 3
01011
Port 11
00100
Port 4
01100
Port 12
00101
Port 5
01101
Port 13
00110
Port 6
01110
Port 14
00111
Port 7
01111
Port 15
10000
Port 16
11000
Port 24
10001
Port 17
11001
Port 25
10010
Port 18
11010
Port 26
10011
Port 19
11011
Port 27
10100
Port 20
11100
Port 28
10101
Port 21
11101
T3/E3 Framer (payload bits only)
10110
Port 22
11110
T3/E3 Framer (payload + overhead bits)
10111
Port 23
11111
Illegal State