Intel® PXA255 Processor Developer’s Manual 4-25

System Integration Unit
4.2.2.5 Interrupt Controller Pending Register (ICPR)

The ICPR, shown in Table 4 -35, is a 32-bit read-only register that shows all active interrupts in the

system. These bits are not affected by the state of the mask register (ICMR). Clearing the interrupt

status bit at the source, automatically clears the corresponding ICPR flag, provided there are no

other interrupt status bits set within the source unit.

Tabl e 4-36 shows the pending interrupt source assigned to each bit position in the ICPR. A ls o

included in the table are the source units for the interrupts and the number of second-level

interrupts associated with each. For more information on the second-level interrupts, see the

section that corresponds to its name in the Source Unit column.

Table 4-35. ICPR Bit Definitions (Sheet 1 of 3)

Physical Address
0x40D0_0010 ICPR System Integration Unit
Bit 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
IS31
IS30
IS29
IS28
IS27
IS26
IS25
IS24
IS23
IS22
IS21
IS20
IS19
IS18
IS17
reserved
IS14
IS13
IS12
IS11
IS10
IS9
IS8
reserved
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Bits Name Description
<31> IS31 RTC Alarm Match Register Interrupt Pending
0 – Interrupt NOT pending due to RTC Alarm Match Register.
1 – Interrupt pending due to RTC Alarm Match Register.
<30> IS30 RTC HZ Clock Tick Interrupt Pending
0 – Interrupt NOT pending due to RTC HZ Clock Tick.
1 – Interrupt pending due to RTC HZ Clock Tick.
<29> IS29 OS Timer Match Register 3 Interrupt Pending
0 – Interrupt NOT pending due to OS Timer Match Register 3.
1 – Interrupt pending due to OS Timer Match Register 3.
<28> IS28 OS Timer Match Register 2 Interrupt Pending
0 – Interrupt NOT pending due to OS Timer Match Register 2.
1 – Interrupt pending due to OS Timer Match Register 2.
<27> IS27 OS Timer Match Register 1 Interrupt Pending
0 – Interrupt NOT pending due to OS Timer Match Register 1.
1 – Interrupt pending due to OS Timer Match Register 1.
<26> IS26 OS Timer Match Register 0 Interrupt Pending
0 – Interrupt NOT pending due to OS Timer Match Register 0.
1 – Interrupt pending due to OS Timer Match Register 0.
<25> IS25 DMA Channel Service Request Interrupt Pending
0 – Interrupt NOT pending due to DMA Channel Service Request.
1 – Interrupt pending due to DMA Channel Service Request.
<24> IS24 SSP Service Request Interrupt Pending
0 – Interrupt NOT pending due to SSP Service Request.
1 – Interrupt pending due to SSP Service Request.
<23> IS23 MMC Status/Error Detection Interrupt Pending
0 – Interrupt NOT pending due to MMC Status/Error Detection.
1 – Interrupt pending due to MMC Status/Error Detection.