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AMD Geode™ SC2200 Processor Data Book 163
Core Logic Module
32580B
6.2.6.3 Programmable Interrupt Controller
The Core Logic module contains two 8259A-equivalent
programmable interrupt controllers, with eight interrupt
request lines each, for a total of 16 interrupts. The PCI
device supports all x86 modes of operation except Special
Fully Nested mode. The two controllers are cascaded inter-
nally, and two of the interrupt request inputs are connected
to the internal circuitry. This allows a total of 13 externally
available interrupt requests. See Figure 6-9.
Each Core Logic IRQ signal can be individually selected to
as edge- or level-sensitive. The four PCI interrupt signals
may be routed internally to any PIC IRQ.
.
Figure 6-8. PIC Interrupt Controllers
Three interrupts are available externally depending upon
selected ball multiplexing:
1) IRQ15 (muxed with GPIO11+RI2#),
2) IRQ14 (muxed with TFTD1), and
3) IRQ9 (muxed with IDE_DATA6)
More of the IRQs are available through the use of SERIRQ
(muxed with GPIO39) function. See Table 6-4.
The Core Logic module allows PCI interrupt signals INTA#,
INTB#, INTC# (muxed with GPIO19+IOCHRDY) and
INTD# (muxed with IDE_DATA7) to be routed internally to
any IRQ signal. The routing can be modified through Core
Logic module’s configuration registers. If this is done, the
IRQ input must be configured to be level- rather than edge-
sensitive. IRQ inputs may be individually programmed to be
level-sensitive with the Interrupt Sensitivity configuration
registers at I/O address space 4D0h and 4D1h. PCI inter-
rupt configuration is discussed in further detail in “PCI
Compatible Interrupts” on page 164.
IR0
IR1
IR2
IR3
IR4
IR5
IR6
IR7
IRQ0
IRQ1
IRQ2
IRQ3
IRQ4
IRQ5
IRQ6
IRQ7
Internal
FPU
8254 Timer 0
RTC_IRQ# IR0
IR1
IR2
IR3
IR4
IR5
IR6
IR7
IRQ8#
IRQ9
IRQ10
IRQ11
IRQ12
IRQ13
IRQ14
IRQ15
INTR
Table 6-4. PIC Interrupt Mapping
Master
IRQ Mapping
IRQ0 Connected to the OUT0 (system timer) of
the internal 8254 PIT.
IRQ2 Connected to the slave’s INTR for a cas-
caded configuration.
IRQ8# Connected to internal RTC.
IRQ13 Connected to the FPU interface of the
GX1 module.
IRQ15 Interrupts available to other functions
IRQ14
IRQ12
IRQ11
IRQ10
IRQ9
IRQ7
IRQ6
IRQ5
IRQ4
IRQ3
IRQ1