Specifications

324 www.xilinx.com Embedded System Tools Guide (EDK 6.2i)
1-800-255-7778 UG111 (v1.4) January 30, 2004
Chapter 23: Interrupt Management
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Figure 23-1: MicroBlaze connected to an Interrupt Source
Figure 23-1 shows MicroBlaze connected to an interrupt source. The interrupt port is
connected to the interrupt port of MicroBlaze. On interrupts, MicroBlaze jumps to address
location 0x8. This is part of the C Runtime library and contains a jump to the default
interrupt handler (_interrupt_handler). This function is part of the MicroBlaze Board
Support Package (BSP) and is provided by Xilinx. It accesses an exception vector to figure
out the name of the interrupt handler for the Interrupt Source. Functions are provided in
the MicroBlaze BSP to change the handler of the Interrupt Source at run time. The Interrupt
Source could be any of the following :
x “Interrupt Controller Peripheral.”
x “Peripheral with an Interrupt port.”
x “External Interrupt Port.”
Each of these cases are explained in detail in the following sections.
Interrupt Controller Peripheral
An interrupt controller peripheral should be used for handling multiple interrupts. In this
case, the user is responsible for writing interrupt handlers for the peripheral interrupt
signals only. The interrupt handler for the interrupt controller peripheral is automatically
generated by libgen tool. This handler ensures that interrupts from the peripherals are
handled by individual interrupt handlers in the order of their priority. Figure 23-2 shows
MicroBlaze Interrupt
Source
interrupt