PSB4596 Siemens Semiconductor Group, PSB4596 Datasheet - Page 60

• Manufacturer Part Number: PSB4596
• Description: Analog Line Interface Solution ALIS
• Manufacturer: Siemens Semiconductor Group

8
There are seven different sources that can cause interrupts in ALIS. The status of these
sources are read from interrupt register XR0. Every interrupt source can be enabled
individually in interrupt-enable register XR1.
To monitor an interrupt source, the corresponding bit must be set in XR1. If an enabled
interrupt indication occurs, the interrupt register XR0 is locked. The lock is released
when the interrupt register XR0 is read. Any interrupt indication occurring during a locked
period will be detected after the lock has been released.
NOTE: An interrupt is only acknowledged when the appropriate bit has been set in the
interrupt-enable register XR1.
The INT pin can be used as an indication to allow external hardware to read the interrupt
register. If the Int_en bit (CR4) is set, the INT pin goes to ’1’ whenever the interrupt
register is locked.
The host must analyze the bits in the interrupt register to determine the cause of the
pending interrupt. All interrupt sources that are not enabled must be ignored by the host
in its analysis. It is possible for several sources together to cause only one interrupt! (i.e.
breakdown of serial connection to ALIS-A: VDD_OK, SI_0, SI_1; if more interrupts occur
during the locked period). If the interrupt was caused by a CADENCE, RING,
CALLER_ID or WAKE_UP interrupt, the indication that caused the pending interrupt is
reset by reading interrupt register XR0.
As only one interrupt can be stored internally, the host must respond immediately to
avoid loss of interrupts.
8.1
There are three different kinds of interrupt indications depending on their source as
shown in the sections below.
Semiconductor Group
Interrupt Controller
Nature and Sources of Interrupts:
60
Analog Line Interface Solution
PSB 4595 / PSB 4596
Interrupt Controller
Data Sheet 06.98