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Question asked by adhawkins on Mar 20, 2013
Latest reply on May 24, 2013 by NateB



I'm trying to make use of interrupts to detect changes in input video format. Initially I'm working with the Composite input, but will extent this to the others once I get this working.


I've written the value 0x09 to IO Map register 0xa0, to enable the SDP_STD_CHANGED and SDP_VIDEO_DET interrupts on IRQ1. I've also set INTRQ_DUR_SEL (bits 6 and 7 of IO Map register 0x40) to b11 (active until cleared).


I don't currently have the interrupt connected (I'm testing using the EVAL-ADV7842-7511P board), but am polling the interrupt status register (0x3f in the IO map) and checking bits 0 and 1 for any indication that an interrupt is present. I am correctly seeing interrupt status register bit for IRQ1 (bit 1 of register 0x3f in the IO map) go high and the SDP_VIDEO_DETECTED_ST bit go high if I remove and reconnect the input source. However, if I change the input format from PAL to NTSC (or vice versa) I do not see the interrupt status register bit for IRQ1 go high as I would expect.


Can you offer any advice as to where I am going wrong? Is there something else I need to set up to receive this interrupt?