DS2154
CRC4 SYNC COUNTER
The CRC4 Sync Counter increments each time the 8 ms CRC4 multiframe search times out. The counter
is cleared when the DS2154 has successfully obtained synchronization at the CRC4 level. The counter
can also be cleared by disabling the CRC4 mode (CCR1.0=0). This counter is useful for determining the
amount of time the DS2154 has been searching for synchronization at the CRC4 level. ITU G.706
suggests that if synchronization at the CRC4 level cannot be obtained within 400 ms, then the search
should be abandoned and proper action taken. The CRC4 Sync Counter will rollover.
SR1: STATUS REGISTER 1 (Address=06 Hex)
(MSB)
(LSB)
RSA1
RDMA
RSA0
RSLIP
RUA1
RRA
RCL
RLOS
SYMBOL
POSITION NAME AND DESCRIPTION
RSA1
SR1.7
Receive Signaling All 1s / Signaling Change. Set when the
contents of timeslot 16 contains less than three 0s over 16
consecutive frames. This alarm is not disabled in the CCS
signaling mode. Both RSA1 and RSA0 will be set if a change in
signaling is detected.
RDMA
RSA0
SR1.6
SR1.5
Receive Distant MF Alarm. Set when bit 6 of timeslot 16 in
frame 0 has been set for two consecutive multiframes. This
alarm is not disabled in the CCS signaling mode.
Receive Signaling All 0s / Signaling Change. Set when over a
full MF, timeslot 16 contains all 0s. Both RSA1 and RSA0 will
be set if a change in signaling is detected.
RSLIP
RUA1
RRA
SR1.4
SR1.3
SR1.2
SR1.1
Receive Side Elastic Store Slip. Set when the elastic store has
either repeated or deleted a frame of data.
Receive Unframed All 1s. Set when an unframed all 1s code is
received at RPOSI and RNEGI.
Receive Remote Alarm. Set when a remote alarm is received at
RPOSI and RNEGI.
RCL
Receive Carrier Loss. Set when 255 (or 2048 if CCR3.0=1)
consecutive 0s have been detected at RTIP and RRING. [Note: a
test mode exists to allow the DS2154 to detect carrier loss at
RPOSI and RNEGI in place of detection at RTIP and RRING].
RLOS
SR1.0
Receive Loss of Sync. Set when the device is not synchronized
to the receive E1 stream.
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DALLAS [ DALLAS SEMICONDUCTOR ]
