
QuadFALCTM
PEF 22554 E
E1 Registers
Data Sheet
404
Rev. 1.2, 2006-01-26
Interrupt Status Register 3
All bits are reset when ISR3 is read. If bit GCR.VIS is set, interrupt statuses in ISR3 are flagged although they are
masked by register IMR3. However, these masked interrupt statuses neither generate a signal on INT (or INT1,
ISR3_E
Offset
Reset Value
Interrupt Status Register 3
xx6BH
00H
Field
Bits
Type
Description
ES
7
rsc
Errored Second
This bit is set if at least one enabled interrupt source by ESM is set during
the time interval of one second. Interrupt sources of ESM register:
LFA = Loss of frame alignment detected (FRS0.LFA)
FER = Framing error received
CER = CRC error received
Alarm indication signal (FRS0.AIS)
Loss-of-signal (FRS0.LOS)
Code violation detected
Receive Slip positive/negative detected
E-Bit error detected (RSP.RS13/15)
SEC
6
rsc
Second Timer
The internal one-second timer has expired. The timer is derived from
clock RCLK or external pin SEC/FSC.
LMFA16
5
rsc
Loss of Multiframe Alignment TS 16
Multiframe alignment of time slot 16 has been lost if two consecutive
multiframe pattern are not detected or if in 16 consecutive time slot 16 all
bits are reset. If register GCR.SCI is high this interrupt status bit is set with
every change of state of FRS1.TS16LFA.
AIS16
4
rsc
Alarm Indication Signal TS 16 Status Change
The alarm indication signal AIS in time slot 16 for the 64 kbit/s channel
associated signaling is detected or cleared. A change in bit
FRS1.TS16AIS sets this interrupt. (This bit is set if the incoming TS 16
signal contains less than 4 zeros in each of two consecutive TS16-
multiframe periods.)
RA16
3
rsc
Remote Alarm Time Slot 16 Status Change
A change in the remote alarm bit in CAS multiframe alignment word is
detected.
RSN
1
rsc
Receive Slip Negative
The frequency of the receive route clock is greater than the frequency of
the receive system interface working clock based on 2.048 MHz. A frame
is skipped. It is set during alarm simulation. See Chapter 4.1.8.