PEB22554 Datasheet, PDF (131/397 Pages) Siemens Semiconductor Group – ICs for Communications

PEB 22554
Pulse Count Detection Register (Read/Write)
Value after RESET: 00_H
7
PCD
PCD7
Operational Description E1
0
PCD0
(x38)
PCD7…PCD0… Pulse Count Detection
A LOS alarm will be detected if the incoming data stream has no
transitions for a programmable number T consecutive pulse
positions. The number T is programmable via the PCD register and
can be calculated as follows:
T= 16(N+1) ; with 0 =< N =< 255.
The maximum time is: 256 x 16 x 488 ns = 2 ms. Every detected pulse
will reset the internal pulse counter. The counter will be clocked with
the receive clock RCLK.
Pulse Count Recovery (Read/Write)
Value after RESET: 00_H
7
0
PCR
PCR7
PCR0 (x39)
PCR7…PCR0… Pulse Count Recovery
A LOS alarm will be cleared if a pulse density is detected in the
received bit stream. The number of pulses M which must occur in the
predefined PCD time interval is programmable via the PCR register
and can be calculated as follows:
M = N+1 ; with 0 =< N =< 255.
The time interval starts with the first detected pulse transition. With
every received pulse a counter will be incremented and the actual
counter is compared with the contents of PCR register. If the pulse
number >= the PCR value the LOS alarm will be reset otherwise the
alarm will still be active. In this case the next detected pulse transition
will start a new time interval.
Semiconductor Group
131
09.98