
QuadFALC
TM
PEF 22554 E
Functional Description E1/T1/J1
Data Sheet
98
Rev. 1.2, 2006-01-26
Figure 20
Interrupt Status Registers
Each interrupt indication bit of the registers ISR(7:0) can be selectively masked by setting the corresponding bit in
the corresponding mask registers IMR(7:0). If the interrupt status bits are masked they neither generate an
interrupt at INT nor are they visible in ISR(7:0).
GIS, the non-maskable “Global” Interrupt Status Register per channel, serves as pointer to pending interrupts
sourced by registers ISR(7:0).
The non-maskable Channel Interrupt Status Register CIS serves as channel pointer to pending interrupts sourced
by registers GIS.
After the QuadFALC
TM has requested an interrupt by activating its INT pin, the external micro controller should
first read the register CIS to identify the requesting interrupt source channel. Then it should read the Global
Interrupt Status register GIS to identify the requesting interrupt source register ISR(7:0) of that channel.
After reading the assigned interrupt status registers ISR(7:0), the pointer bit in register GIS is cleared or updated
if another interrupt requires service. After all bits ISR(7:0) of a register GIS are cleared, the assigned bit in register
CIS is cleared. After all bits in register CIS are cleared the INT pin will be deactivated.
If all pending interrupts are acknowledged by reading (GIS is reset), pin INT goes inactive.
Updating of interrupt status registers ISR(7:0) and GIS is only prohibited during read access.
IMR0
Global“
Interrupt Status
Register GIS
(per channel)
ISR0
IMR1
ISR1
IMR2
ISR2
IMR3
ISR3
IMR4
ISR4
IMR5
ISR5
QFALCv3_ISR_F0127
IMR6
ISR6
IMR7
ISR7
ISR0
ISR1
ISR2
ISR3
ISR4
ISR5
ISR6
ISR7
ISR0
ISR1
ISR2
ISR3
ISR4
ISR5
ISR6
ISR7
ISR0
ISR1
ISR2
ISR3
ISR4
ISR5
ISR6
ISR7
GIS4
ISR0
ISR1
ISR2
ISR3
ISR4
ISR5
ISR6
ISR7
GIS1
GIS2
GIS3
PLLLS
Status Registers and Masking
(shownfor one channel)
Channel
Interrupt Status
Register CIS ,
global
channel
...
different Status bits
...
INT
PLL
PLLLC
PLLL
GIS2
GIMR
VIS
GCR
VISPLL IPC
not visible for
GPC1.COMP_DIS
=1