pef2256e Infineon Technologies Corporation, pef2256e Datasheet - Page 304

• Manufacturer Part Number: pef2256e
• Description: E1/t1/j1 Framer And Line Interface Component For Long- And Short-haul Applications
• Manufacturer: Infineon Technologies Corporation

Framer Receive Status Register 0 (Read)
FRS0
LOS
AIS
User’s Manual
Hardware Description
LOS
7
Loss-of-Signal
Detection:
This bit is set when the incoming signal has “no transitions” (analog
interface) or logical zeros (digital interface) in a time interval of T
consecutive pulses, where T is programmable by register PCD.
Total account of consecutive pulses: 16 < T < 4096.
Analog interface: The receive signal level where “no transition” is
declared is defined by the programmed value of LIM1.RIL(2:0).
Recovery:
Analog interface: The bit is reset in short-haul mode when the
incoming signal has transitions with signal levels greater than the
programmed receive input level (LIM1.RIL(2:0)) for at least M pulse
periods defined by register PCR in the PCD time interval. In long-haul
mode additionally bit RES.6 must be set for at least 250µsec.
Digital interface: The bit is reset when the incoming data stream
contains at least M ones defined by register PCR in the PCD time
interval.
With the rising edge of this bit an interrupt status bit (ISR2.LOS) is set.
The bit is also set during alarm simulation and reset, if FMR0.SIM is
cleared and no alarm condition exists.
Alarm Indication Signal
The function of this bit is determined by FMR0.ALM.
FMR0.ALM = 0: This bit is set when two or less zeros in the received
bit stream are detected in a time interval of 250 µs and the FALC
is in asynchronous state (FRS0.LFA = 1). The bit is reset when no
alarm condition is detected (according to ETSI standard).
FMR0.ALM = 1: This bit is set when the incoming signal has two or
less Zeros in each of two consecutive double frame period (512 bits).
This bit is cleared when each of two consecutive doubleframe periods
contain three or more zeros or when the frame alignment signal FAS
has been found. (ITU-T G.775)
The bit is also set during alarm simulation and reset if FMR0.SIM is
cleared and no alarm condition exists.
With the rising edge of this bit an interrupt status bit (ISR2.AIS) is set.
AIS
LFA
RRA
304
NMF
LMFA
DS1.1, 2003-10-23
PEF 2256 H/E
E1 Registers
0
FALC
(4C)
®
®
56
56