
QuadFALCTM
PEF 22554 E
T1/J1 Registers
Data Sheet
586
Rev. 1.2, 2006-01-26
Framer Receive Status Register 1
FRS1_T
Offset
Reset Value
Framer Receive Status Register 1
xx4DH
xxH
Field
Bits
Type
Description
EXZD
7
r
Excessive Zeros Detected
Significant only if excessive zeros detection is enabled (FMR2.EXZE =
1B).
Set after detecting of more than 7 (B8ZS code) or more than 15 (AMI
code) contiguous zeros in the received bit stream. This bit is cleared on
read.
PDEN
6
r
Pulse-Density Violation Detected
The pulse-density of the received data stream is below the requirement
defined by ANSI T1. 403 or more than 14 consecutive zeros are detected.
With the violation of the pulse-density this bit is set and remains active
until the pulse-density requirement is fulfilled for 23 consecutive "1"-
pulses. Additionally an interrupt status ISR0.PDEN is generated with the
rising edge of PDEN.
LLBDD
4
r
Line Loop-Back Deactivation Signal Detected
This bit is set in case of the LLB deactivate signal is detected and then
received over a period of more than 33,16 ms with a bit error rate less
than 10-2. The bit remains set as long as the bit error rate does not exceed
10-2. If framing is aligned, the first bit position of any frame is not taken
into account for the error rate calculation.Any change of this bit causes an
LLBSC interrupt.
LLBAD
3
r
Line Loop-Back Activation Signal Detected PRBS Status
Depending on bit LCR1.EPRM the source of this status bit changed.
LCR1.EPRM = 0B: This bit is set in case of the LLB activate signal is
detected and then received over a period of more than 33,16 ms with
a bit error rate less than 10-2. The bit remains set as long as the bit
error rate does not exceed 10-2. If framing is aligned, the first bit
position of any frame is not taken into account for the error rate
calculation. Any change of this bit causes an LLBSC interrupt.
LCR1.EPRM = 1B: The current status of the PRBS synchronizer is
indicated in this bit. It is set high if the synchronous state is reached
even in the presence of a bit error rate of up to 10-3. A data stream
containing all zeros or all ones with/without framing bits is also a valid
pseudo-random binary sequence.