Bt8370/8375/8376
3.8 Receiver Registers
Fully Integrated T1/E1 Framer and Line Interface
RLOF
Receive Loss of Frame Alignment—Real-time or integrated RLOF status depends on selected
receive framer mode, out of frame criteria [RLOFA–RLOFD; addr 040], and integration mode
[RLOF_INTEG; addr 045]. Refer to Table A-1 through A-7 in Appendix A to find which
frame bits are monitored. Refer to Table 3-2, Receive Framer Modes for loss/recovery criteria.
During E1 mode, RLOF indicates the logically OR'ed status of FAS/MFAS/CAS alignment
machines from which individual alignment status is reported separately in
FRED/MRED/SRED [addr 049].
0 = no alarm
1 = receive loss of frame alignment
SIGFRZ
Signaling Freeze—Real-time SIGFRZ status indicates when input ABCD signaling bit
updates are no longer being written to the receive signaling buffer [RSIGn; addr IA0–IBF].
Consequently, ABCD signaling on RPCMO (if signaling insertion is enabled) and RSIGO
output pins are fixed to their existing buffered values. SIGFRZ remains active for 6 to 12 ms
longer after COFA or RLOF clears. SIGFRZ status is also affected by manual SIGFRZ on/off
controls [RSIG_CR; addr 0D7].
0 = no alarm (or FRZ_OFF)
1 = signaling freeze (or FRZ_ON)
048—Alarm 2 Status (ALM2)
Reports real-time status of transmit alarms and inband loopback codeword detectors. Any change in the current
status activates the corresponding interrupt status bit [ISR6; addr 005].
7
6
5
4
3
2
1
0
LOOPDN
LOOPUP
—
TSHORT
TLOC
—
TLOF
—
LOOPDN
Inband Loopback Deactivate—Reports detection or loss of an inband loopback code which
matches the programmed LOOPDN code [LBD; addr 044].
0 = no inband code (or lost)
1 = LOOPDN code detected
LOOPUP
TSHORT
Inband Loopback Activate—Reports detection or loss of an inband loopback code which
matches the programmed LOOPUP code [LBA; addr 043].
0 = no inband code (or lost)
1 = LOOPUP code detected
Transmit Short Circuit—Indicates transmit line driver output has reached its 50 mA current
limit, which is typically caused by either a short circuited transmit cable or transmission line
transient surge current.
0 = normal
1 = short circuit (50 mA current limited)
TLOC
Transmit Loss of Clock—Clock monitor circuit reports that transmit clock (TXCLK) is lost if
no signal transitions are detected for 8 clock cycles of ACKI. TXCLK is reported as present if
four or more signal transitions are detected during 8 clock cycles of ACKI. When used in
conjunction with AISCLK [addr 068], TLOC also identifies if ACKI is in use and AIS data
transmission is enforced. TLOC status is indeterminate if the ACKI input signal is not present.
0 = transmit clock present
1 = transmit clock lost
TLOF
Transmit Loss of Frame Alignment—Reports transmit framer status per selected mode
[TFRAME; addr 070] and loss criteria [TLOFA–TLOFC; addr 071].
0 = recovered
1 = lost
3-56
Conexant
N8370DSE
CONEXANT [ CONEXANT SYSTEMS, INC ]
