AN1849 Motorola / Freescale Semiconductor, AN1849 Datasheet - Page 24

• Manufacturer Part Number: AN1849
• Description: MPC107 Design Guide
• Manufacturer: Motorola / Freescale Semiconductor

As shown in Figure 17, the EPIC gathers a variety of internal and external interrupts sources and forwards
them to the processor. Interrupts can be masked, prioritized, and set to various combinations of polarity and
edge-/level-sensitivity.
The connections of the interrupt pins vary depending on the application. For agent boards, which do not
typically handle external interrupts, INTA is connected to the INTA# pin of the PCI card or the appropriate
INTA#-INTD# pins of the PCI host.
For host boards, the INTA pin is typically not used, and INT(0:4) is connected to the interrupt pins
(INTA#-INTD#) of the various PCI interrupt sources.
1.8.1 Serial Interrupt Expansion
The MPC107 can directly accept up to 5 external interrupts with no additional hardware support. If
additional interrupts are needed, up to 16 external interrupts can be supported by inserting a
serially-controlled multiplexer. The EPIC demultiplexes the serial data stream and drives internal interrupt
lines accordingly. The hardware requirements are minimal and can be easily supported in a complex PLD,
FPGA or ASIC (but more than a 22LV10 will handle).
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INT(0:4)
INTA
5
Figure 17. MPC107 EPIC Interrupt Connections
TIMERS
DMA
I2O
PIC
MPC107 Design Guide
MPC107
EPIC
16
4
2
2
ISR
INT
MPC7400