Datasheet

DS2155
67 of 238
Register Name:
SR4
Register Description:
Status Register 4
Register Address:
1Ch
Bit # 7 6 5 4 3 2 1 0
Name RAIS-CI RSAO RSAZ TMF TAF RMF RCMF RAF
Default 0 0 0 0 0 0 0 0
Bit 0/Receive Align Frame Event (RAF) (E1 Only). Set every 250µs at the beginning of align frames. Used to
alert the host that Si and Sa bits are available in the RAF and RNAF registers.
Bit 1/Receive CRC4 Multiframe Event (RCMF) (E1 Only). Set on CRC4 multiframe boundaries; continues to
set every 2ms on an arbitrary boundary if CRC4 is disabled.
Bit 2/Receive Multiframe Event (RMF)
E1 Mode: Set every 2ms (regardless if CAS signaling is enabled or not) on receive multiframe boundaries.
Used to alert the host that signaling data is available.
T1 Mode: Set every 1.5ms on D4 MF boundaries or every 3ms on ESF MF boundaries.
Bit 3/Transmit Align Frame Event (TAF) (E1 Only). Set every 250µs at the beginning of align frames. Used to
alert the host that the TAF and TNAF registers need to be updated.
Bit 4/Transmit Multiframe Event (TMF)
E1 Mode: Set every 2ms (regardless if CRC4 is enabled) on transmit multiframe boundaries. Used to alert
the host that signaling data needs to be updated.
T1 Mode: Set every 1.5ms on D4 MF boundaries or every 3ms on ESF MF boundaries.
Bit 5/Receive Signaling All-Zeros Event (RSAZ) (E1 Only). Set when over a full MF, time slot 16 contains
all 0s.
Bit 6/Receive Signaling All-Ones Event (RSAO) (E1 Only). Set when the contents of time slot 16 contains fewer
than three 0s over 16 consecutive frames. This alarm is not disabled in the CCS signaling mode.
Bit 7/Receive AIS-CI Event (RAIS-CI) (T1 Only). Set when the receiver detects the AIS-CI pattern as defined in
ANSI T1.403.