PEB2085 SIEMENS [Siemens Semiconductor Group], PEB2085 Datasheet - Page 165

• Manufacturer Part Number: PEB2085
• Description: ISDN SubscribernAccess Controller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Figure 69
INT Handling
Figure 70
Service Program for Edge-Triggered Interrupt Controllers
Semiconductor Group
INT
A status bit is set. This causes an interrupt.
The microprocessor starts its service routine and reads the status registers.
A new status bit is set before the first status bit has been read.
The first status bit is read.
The INT output stays active but the interrupt controller will not serve the interrupt
(edge triggered).
to
’FF’ is written to the MASK register. This masks all interrupts and returns the INT
output to its inactive state.
The old value is written to the MASK register. This will activate the INT output if
an interrupt source is still active.
The microprocessor starts a new interrupt service program.
The last status bit is read.
The INT output is inactive.
see above
INT
165
Operational Description