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Diffstat (limited to 'bsps/powerpc/mvme5500/README.irq')
| -rw-r--r-- | bsps/powerpc/mvme5500/README.irq | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/bsps/powerpc/mvme5500/README.irq b/bsps/powerpc/mvme5500/README.irq new file mode 100644 index 0000000000..fb31c4a5c3 --- /dev/null +++ b/bsps/powerpc/mvme5500/README.irq @@ -0,0 +1,20 @@ +README.irq : Shuchen Kate Feng <feng1@bnl.gov>, Sept. 2, 2007 + +As per implementation in shared PPC code, +the BSPirqPrioTable[96] listed in irq_init.c is where the +software developers can change the levels of priority +for all the interrupts based on the need of their +applications. The IRQs can be eanbled dynamically via the +BSP_enable_pic_irq(), or disbaled dynamically via the +BSP_disable_pic_irq(). + + +Support for run-time priority setup could be +added easily, but there is no action taken yet due to concerns +over computer security at VME CPU level. + + +The software developers are forbidden to setup picIsrTable[], +as it is a powerful engine for the BSP to find the pending +highest priority IRQ at run time. It ensures the fastest/faster +interrupt service to the highest/higher priority IRQ, if pending. |