- 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.
Figure 2-2 Startup Flow