
DS21Q58 E1 Quad Transceiver
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10.3 E-Bit/PRBS Bit-Error Counter
E-bit count register 1 (EBCR1) is the most significant word and EBCR2 is the least significant word of a 16-bit
counter that records far-end block errors (FEBE) as reported in the first bit of frames 13 and 15 on E1 lines running
with CRC4 multiframe. These error count registers increment once each time the received E-bit is set to 0. Since
the maximum E-bit count in a one-second period is 1000, this counter cannot saturate. The counter is disabled
during loss of sync at either the FAS or CRC4 level; it continues to count if loss-of-multiframe sync occurs at the
CAS level.
Alternately, this counter counts bit errors in the received PRBS pattern when the receive PRBS function is enabled.
In this mode, the counter is active when the receive PRBS detector can synchronize to the PRBS pattern. This
pattern can be framed, unframed, or in any time slot. See Section
13 for more details.
Register Name:
EBCR1, EBCR2
Register Description:
E-Bit Count Registers
Register Address:
04 Hex, 05 Hex
Bit #
7
6
5
4
3
2
1
0
EB15
EB14
EB13
EB12
EB11
EB10
EB9
EB8
Name
EB7
EB6
EB5
EB4
EB3
EB2
EB1
EB0
NAME
BIT
FUNCTION
EB15
EBCR1.7
MSB of the 16-bit E-bit error count.
EB0
EBCR2.0
LSB of the 16-bit E-bit error count.
10.4 FAS Error Counter
FAS count register 1 (FASCR1) is the most significant word and FASCR2 is the least significant word of a 16-bit
counter that records word errors in the FAS in time slot 0. This counter is disabled when RLOS is high. FAS errors
are not counted when the framer is searching for FAS alignment and/or synchronization at either the CAS or CRC4
multiframe level. Since the maximum FAS word error count in a one-second period is 4000, this counter cannot
saturate.
Register Name:
FASCR1, FASCR2
Register Description:
FAS Error Count Registers
Register Address:
06 Hex, 07 Hex
Bit #
7
6
5
4
3
2
1
0
FAS15
FAS14
FAS13
FAS12
FAS11
FAS10
FAS9
FAS8
Name
FAS7
FAS6
FAS5
FAS4
FAS3
FAS2
FAS1
FAS0
NAME
BIT
FUNCTION
FAS15
FASCR1.7
MSB of the 16-bit FAS error count.
FAS0
FASCR2.0
LSB of the 16-bit FAS error count.