Bt8370/8375/8376
3.0 Registers
Fully Integrated T1/E1 Framer and Line Interface
3.4 Interrupt Status Registers
3.4 Interrupt Status Registers
Unused bits indicated by a dash (—) are reserved and should be written to 0. Writing to reserved bits has no
effect.
An Interrupt Status register (ISR) bit is latched active (high) whenever its corresponding interrupt source
reports an interrupt event. The processor reads ISR to clear all latched ISR bits. If the corresponding interrupt
enable is active (high), each interrupt event forces the associated IRR bit active (high) and the INTR* output pin
active (low). Interrupt sources fall into two categories:
• Rising-edge source reports an interrupt event when status changes from inactive to active state. Unless
specifically noted otherwise, all ISR bits are rising-edge sources.
• Dual-edge source reports an interrupt event when status changes from inactive to active (rising edge),
or from active to inactive (falling edge). The processor must read the associated real-time status to
determine which edge occurred.
Interrupt events are reported in real time on the INTR* output pin if the interrupt enable is active (high).
Otherwise, the interrupt status is latched and reported according to the selected latching mode [LATCH;
addr 046] without asserting the INTR* output pin. Table 3-3 summarizes the interrupt status registers.
Table 3-3. Interrupt Status Register Summary
004
ISR7
ALARM1
005
ISR6
ALARM2
006
ISR5
ERROR
007
ISR4
COUNT
008
ISR3
TIMER
009
ISR2
DL1
00A
ISR1
DL2
00B
ISR0
PATT
Bit
(1)
0
1
2
3
4
5
6
7
SIGFRZ
RLOF
ONESEC
TLOF
FERR
MERR
SERR
CERR
JERR
FERR[12]
CRC[10]
LCV[16]
FEBE[10]
BERR[12]
SEF[2]
RFRAME
RMF
TMSG
TNEAR
TEMPTY
TDLERR
RMSG
RNEAR
RFULL
TBOP
TFERR
TMERR
TSERR
TCERR
PSYNC
BSLIP
—
TMSG
TNEAR(1)
(1)
RLOS
—
RMSYNC
RSIG
TEMPTY
TDLERR(1)
RALOS
RAIS
TLOC
(1)
TSHORT
TPDV
TFRAME
TMF
RMSG
RNEAR(1)
RPDV
RYEL
CKERR
RSLIP
TSLIP
(1)
LOOPUP
LOOPDN
COFA[2]
RLOF[4]
TMSYNC
TSIG
RFULL
RMYEL
RBOP
—
NOTE(S):
(1)
These bits are not active in the Bt8376 Device.
N8370DSE
Conexant
3-15
CONEXANT [ CONEXANT SYSTEMS, INC ]
