DLPU100B May 2020 – June 2024 DLP2021-Q1 , DLP3021-Q1
HOST IRQ is a level interrupt output from the FPGA. Multiple internal interrupt sources can trigger the external interrupt signal. If the signal is low, all of the enabled interrupt sources are cleared. If the signal is high, one of the sources is enabled and has been triggered. Three registers are used for handling the interrupt sources:
FPGA Interrupt Enable is used to mask which interrupt sources will trigger the external HOST IRQ signal. For example, if the “video loop complete” enable bit is set to 1, then this source will set HOST IRQ high when triggered. If it is set to 0, then HOST IRQ will not be set high due to this source.
FPGA Interrupt Set is used to read back the currently set interrupts. Once an internal interrupt source is set, it will remain set until it is cleared by writing to the FPGA Interrupt Clear register.
FPGA Interrupt Clear is used to clear interrupt sources once handled. Typically, the FPGA Interrupt Set register can be directly written to the FPGA Interrupt Clear register in order to clear all currently active interrupts. Then, the host MCU can determine what action to take based on the interrupts that were set.
HOST IRQ will remain high if multiple enabled interrupt sources trigger.