AR# 36594: Design Assistant for PCI Express - How do I configure the core in order to use MSI or Legacy Interrupt?
AR# 36594
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Design Assistant for PCI Express - How do I configure the core in order to use MSI or Legacy Interrupt?
描述
How is the core configured to use MSI or Legacy Interrupts? NOTE: This Answer Record is part of the Xilinx Solution Center for PCI Express(Xilinx Answer 34536) Solution Center for PCI Express is available to address all questions related to PCIe. Whether you are starting a new design with PCIe or troubleshooting a problem, use the Solution Center for PCIeto guide you to the right information.
解决方案
The use of MSI or legacy interrupts depends on whether the MSI enable bit is set in the MSI control register. The MSI enable bit is bit 0 of the MSI control register. The MSI control register is part of the MSI capability set. For more information on the MSI capability, see Chapter 6 of the PCI Local Bus Specification v3.0. The enable bit is set by a configuration write from the host. The user application cannot set this bit. Once set, the core asserts the cfg_msienable_n output to the user application. If the MSI enable bit is not set then legacy interrupts are used by default.