Manual

DS2143/DS2143Q
031397 13/40
CRC4 SYNC COUNTER
The CRC4 Sync Counter increments each time the 8ms
CRC4 multiframe search times out. The counter is
cleared when the DS2143 has successfully obtained
synchronization at the CRC4 level. The counter can
also be cleared by disabling the CRC4 mode
(CCR.0=0). This counter is useful for determining the
amount of time the DS2143 has been searching for syn-
chronization at the CRC4 level. Annex B of CCITT
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 SLIP RUA1 RRA RCL RLOS
SYMBOL POSITION NAME AND DESCRIPTION
RSA1 SR1.7 Receive Signaling All Ones. Set when the contents of timeslot 16 con-
tains less than 3 zeros over 16 consecutive frames. This alarm is not dis-
abled in the CCS signaling mode.
RDMA SR1.6 Receive Distant MF Alarm. Set when bit 6 of timeslot 16 in frame 0 has
been set for 2 consecutive multiframes. This alarm is not disabled in the
CCS signaling mode.
RSA0 SR1.5 Receive Signaling All Zeros. Set when over a full MF, timeslot 16 con-
tains all zeros.
SLIP SR1.4 Elastic Store Slip Occurrence. Set when the elastic store has either
repeated or deleted a frame of data.
RUA1 SR1.3 Receive Unframed All Ones. Set when an unframed all ones code is
received at RPOS and RNEG.
RRA SR1.2 Receive Remote Alarm. Set when a remote alarm is received at RPOS
and RNEG.
RCL SR1.1 Receive Carrier Loss. Set when 255 consecutive zeros have been
detected at RPOS and RNEG.
RLOS SR1.0 Receive Loss of Sync. Set when the device is not synchronized to the
receive E1 stream.