- The HOST_IRQ signal is provided to indicated when the system has completed auto-initialization.
- While reset is applied, HOST_IRQ is tri-stated (an external pullup resistor pulls the line high).
- HOST_IRQ remains tri-stated (pulled high externally) until the boot process completes. While the signal is pulled high, this indicates that the controller is performing boot-up and auto-initialization.
- As soon as possible after the controller boots-up, the controller drives HOST_IRQ to a logic high state to indicate that the controller is continuing to perform auto-initialization (no real state changes occur on the external signal).
- The software sets HOST_IRQ to a logic low state at the completion of the auto-initialization process. At the falling edge of the signal, the initialization is complete.
- The DLPC34xx controller is ready to receive commands through I2C or accept video over the DSI or the parallel interface only after auto-initialization is complete.
- The controller initialization typically completes (HOST_IRQ goes low) within 500 ms of RESETZ being asserted. However, this time may vary depending on the software version and the contents of the user configurable auto initialization file.