The next stage of INTC is to enable interrupts based on programmed settings. The following sequence has to be followed to enable interrupts:
- Enable required interrupts: System interrupts that are required to get propagated to host are to be enabled individually by writing to [9-0] ENABLE_SET_INDEX bit field in the interrupt enable indexed set register (ICSS_INTC_ENABLE_SET_INDEX_REG). The interrupt to enable is the index value written. This sets the Enable Register bit of the given index.
- Enable required host interrupts: By writing 1h to the appropriate bit of the [9-0] HINT_ENABLE_SET_INDEX bit field in the host interrupt enable indexed set register (ICSS_INTC_HINT_ENABLE_SET_INDEX_REG), enable the required host interrupts. The host interrupt to enable is the index value written. This enables the host interrupt output or triggers the output again if that host interrupt is already enabled.
- Enable all host interrupts: By setting the [0] ENABLE_HINT_ANY bit in the global enable register (ICSS_INTC_GLOBAL_ENABLE_HINT_REG) to 1h, all host interrupts will be enabled. Individual host interrupts are still enabled or disabled from their individual enables and are not overridden by the global enable.