9-12 SA-1100
Developer’s Manual
System Control Module
9.2.1.1 Interrupt Controller Pending Register (ICPR)
The ICPR 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). The following table shows the pending
interrupt source assigned to each bit position in the ICPR. Also included in the table are the source
units for the interrupts and the number of second-level interrupts associated with each. For more
detail on the second-level interrupts, see the section describing that unit.
Several units have more than one source per interrupt signal. When an interrupt is signalled from
one of these units, the interrupt handler routine identifies which interrupt was signalled using the
interrupt controller’s flag register (this identifies the unit that made the request, but not the exact
source). The handler then reads the interrupting unit’s status register to identify which source
within the unit signalled the interrupt. For all interrupts that have one corresponding source, the
interrupt handler routine needs to use only the interrupt controller’s registers to identify the exact
cause of the interrupt.
Bit Position Unit Source Module # of Level 2 Sources Bit Field Description
IP<31>
System
Real-time clock 1 RTC equals alarm register.
IP<30> 1 One Hz clock TIC occurred.
IP<29>
Operating system timer
1 OS timer equals match register 3.
IP<28> 1 OS timer equals match register 2.
IP<27> 1 OS timer equals match register 1.
IP<26> 1 OS timer equals match register 0.
IP<25>
Peripheral
DMA controller 3 Channel 5 service request.
IP<24> 3 Channel 4 service request.
IP<23> 3 Channel 3 service request.
IP<22> 3 Channel 2 service request.
IP<21> 3 Channel 1 service request.
IP<20> 3 Channel 0 service request.
IP<19> Serial port 4b 3 SSP service request.
IP<18> Serial port 4a 8 MCP service request.
IP<17> Serial port 3 6 UART service request.
IP<16> Serial port 2 6+6 UART/HSSP service request.
IP<15> Serial port 1b 6 UART service request.
IP<14> Serial port 1a 5 SDLC service request.
IP<13> Serial port 0 6 UDC service request.
IP<12> LCD controller 12 LCD controller service request.
IP<11> System General-purpose I/O 17 “OR” of GPIO edge detects 27-11.
IP<10> 1 GPIO<10> edge detect.
IP<9> 1 GPIO<9> edge detect.
IP<8> 1 GPIO<8> edge detect.
IP<7> 1 GPIO<7> edge detect.
IP<6> 1 GPIO<6> edge detect.
IP<5> 1 GPIO<5> edge detect.
IP<4> 1 GPIO<4> edge detect.
IP<3> 1 GPIO<3> edge detect.
IP<2> 1 GPIO<2> edge detect.
IP<1> 1 GPIO<1> edge detect.
IP<0> 1 GPIO<0> edge detect.
Total level 2 interrupt
sources 110