The 2D-LSC module can generate events on a single interrupt line. These events are further remapped at the ISP level in the ISP5_IRQENABLE_SET_i[3] ISIF_INT_3 bit, where i = 0 to 3.
Four 2D-LSC events can be generated:
- DONE: LSC done. This event triggers when the LSC submodules transition from ACTIVE state to IDLE state.
- PREFETCH_ERROR: Gain table prefetch error. This event triggers when the tables stored in SDRAM are read too slowly. After this event is asserted, the LSC disables the LSC computation until the beginning of the next frame.
- PREFETCH_COMPLETE: Gain table prefetch complete. This event triggers when data prefetching from SDRAM completes. Data prefetching must complete by the time the first pixel of a frame arrives. The event triggers when the buffer contains three full rows of data.
- SOF: This event signals the start of the LSC valid region. The LSC configuration registers for the next frame can be updated after the LSC SOF triggers.
The ISIF_2DLSCIRQEN register can be configured to select which events are masked and which are propagated to the LSC interrupt signal. The ISIF_2DLSCIRQST register can be read and cleared to identify which events have occurred.
In addition, the 2D-LSC module provides the following status bit:
- BUSY: This indicates that LSC has entered the active region vertically. This bit remains on during horizontal blanking, and turns off only after the entire active region of the current frame is processed.