PM4328-PI PMC-Sierra, Inc., PM4328-PI Datasheet - Page 152

• Manufacturer Part Number: PM4328-PI
• Description: Framer, T1|E1|T3 Standard Format, 324-BGA
• Manufacturer: PMC-Sierra, Inc.

STANDARD PRODUCT
DATASHEET
PMC-2011596
PROPRIETARY AND CONFIDENTIAL
Figure 29: CRCE Count vs. BER (E1 mode)
Figure 30 illustrates the expected count values for a range of Bit Error Ratios in
T1 mode.
Figure 30: FER Count vs. BER (T1 ESF mode)
Since the maximum number of ESF superframes that can occur in one second is
333, the 9-bit BEE counter cannot saturate in one second in ESF framing format.
Despite this, there is not a linear relationship between BER and BEE count, due
to the nature of the CRC-6 calculation. At BERs below 10
more than one bit error per superframe, so the number of CRC-6 errors is
generally equal to the number of bit errors, which is directly related to the BER.
However, at BERs above 10
bit error. Thus, the relationship between BER and BEE count becomes non-
linear above a 10
CRC-6 counts to determine the BER.
1.00E-02
1.00E-03
1.00E-04
1.00E-05
1.00E-06
1.00E-07
- 2
R
E
B
0
1
( x
t e
a
o
)
r
r r
i t
-4
0
BER. This must be taken into account when using ESF
9
8
7
6
5
4
3
2
1
0
0
ISSUE 1
Many 1 Second Intervals
Average Count Over
200
50
-4
, each CRC-6 error is often due to more than one
Framing Bit Error Count Per Second
400
100
139
CRCE
600
150
800
200
1000
250
-4
, there tends to be no
HIGH DENSITY T1/E1 FRAMER
1200
AND M13 MULTIPLEXER
PM4328 TECT3