peb3456 Infineon Technologies Corporation, peb3456 Datasheet - Page 99

• Manufacturer Part Number: peb3456
• Description: Channelized T3 Termination With Ds3 Framer, M13 Multiplexer, T1/ E1 Framers And 256 Channel Hdlc/ppp Controller
• Manufacturer: Infineon Technologies Corporation

Error Counter
The TE3-CHATT framer offers four error counters, each of them has a length of 16 bit.
They record framing bit errors, CRC-4 bit errors. Updating the buffer is done in two
modes:
- one second boundary
- clear on read
In the one second mode an internal one second timer will update these buffers and reset
the counter to accumulating the error events. The error counter can not overflow. Error
events occurring during reset will not be lost.
Status: Errored Second
TE3-CHATT supports the error performance monitoring by detecting alarms or error
events in the received data.
Loss of frame alignment, including alarm indication signal and loss of signal, as well as
CRC errors could generate an Errored Second interrupt if enabled.
Second Timer
An one-second timer interrupt could be internally generated to indicate that the enabled
alarm status bits or the error counters have to be checked.
4.7.3.2
The TE3-CHATT can be programmed to satisfy the different definitions for detecting
Loss of Signal (LOS) alarms in ITU-T G.775 and ETS 300233. Loss of signal is indicated
by a flag in the receive framer's status register (FRS.LOS). In addition, a ’Loss of Signal
Status’ interrupt vector is generated, if not masked.
Detection
’Loss of Signal’ alarm will be generated, if the incoming data stream has no pulses (no
’1’) for a certain number N of consecutive pulse periods. ’No pulse’ in the receive
interface means a logical zero on receive data inputs. The number N can be set via
register PCD and is calculated as 8*(PCD+1).
Automatic remote alarm access
If the receiver has lost its synchronization a remote alarm could be sent if enabled via
TFMR.AXRA to the distant end. The remote alarm bit will be automatically set in the
outgoing data stream if the receiver is in asynchronous state (FRS.LFA bit is set). In
synchronous state the remote alarm bit will be removed.
Data Sheet
Loss of Signal Detection
99
Functional Description
PEB 3456 E
05.2001