
FALC56 V1.2
PEB 2256
Functional Description E1
Data Sheet
92
2002-08-27
loss of CAS multiframe alignment or a receive slip occurs. The internal signaling buffer
RS(16:1) is frozen. Optionally automatic freeze signaling is disabled by setting bit
SIC3.DAF.
4.3.3
Error Counter
The FALC56 offers six error counters where each of them has a length of 16 bit. They
record code violations, framing bit errors, CRC4-bit errors and CRC4 error events which
are flagged in the different S
a
6-bit combinations or the number of received multiframes
in asynchronous state or the change of frame alignment (COFA). Counting of the
multiframes in the asynchronous state and the COFA parameter is done in a 6/2 bit
counter and is shared with CEC3L/H. Each of the error counters is buffered. Buffer
updating is done in two modes:
One-second accumulation
On demand by handshake with writing to the DEC register
In the one-second mode an internal/external one-second timer updates these buffers
and resets the counter to accumulate the error events in the next one-second period.
The error counter cannot overflow. Error events occurring during an error counter reset
are not lost.
4.3.4
Errored Second
The FALC56 supports the error performance monitoring by detecting the following
alarms or error events in the received data:
framing errors, CRC errors, code violations, loss of frame alignment, loss-of-signal,
alarm indication signal, E-bit error, receive and transmit slips.
With a programmable interrupt mask register ESM all these alarms or error events can
generate an errored second interrupt (ISR3.ES) if enabled.
4.3.5
One-Second Timer
Additionally, a one-second timer interrupt can be generated internally to indicate that the
enabled alarm status bits or the error counters have to be checked. The one-second
timer signal is output on port SEC/FSC (GPC1.CSFP1/0). Optionally synchronization to
an external second timer is possible which has to be provided on pin SEC/FSC.
Selecting the external second timer is done with GCR.SES. Refer also to register GPC1
for input/output selection.
4.3.6
In-Band Loop Generation and Detection
The FALC56 generates and detects a framed or unframed in-band loop-up (activate) and
loop-down (deactivate) pattern with bit error rates up to 10
-2
. Framed or unframed in-
band loop code is selected by LCR1.FLLB. Replacing transmit data with the in-band loop
codes is done by programming FMR3.XLD/XLU.