topic Re: RT1052: Can CSI VSYNC be set to falling-edge triggered? in i.MX RT Crossover MCUs

RT1052: Can CSI VSYNC be set to falling-edge triggered?

udoeb — Fri, 20 Jan 2023 17:14:40 GMT

Hello,

The manual states in section 34.3.1.2 Gated Clock Mode:

The CSI can be programmed to support rising/falling-edge
triggered VSYNC through CSI_CR1[SOF_POL]

However, when I set SOF_POL=1 this has no effect. CSI still triggers on rising edge.

I'm using traditional interface, CCIR_EN=0, CCIR_MODE=0, EXT_VSYNC=0.

Question: How can VSYNC be configured for falling edge?

Thanks
Udo

Re: RT1052: Can CSI VSYNC be set to falling-edge triggered?

jingpan — Mon, 30 Jan 2023 07:37:12 GMT

Hi @udoeb ,

This is a interrupt control bit. Can you share how to test this condition?

Regards,

Jing

Re: RT1052: Can CSI VSYNC be set to falling-edge triggered?

udoeb — Mon, 06 Feb 2023 08:54:48 GMT

Hi,

Thanks for your reply.

Let me rephrase the question: I do apply an external signal to VSYNC and notice that the DMA starts on the rising edge. My external circuitry requires that DMA starts on the falling edge. How can I achieve that?

Regards,
Udo

Re: RT1052: Can CSI VSYNC be set to falling-edge triggered?

jingpan — Wed, 08 Feb 2023 07:23:33 GMT

Hi,

But SOF_POL default is 0, it is falling edge. SOF_POL=1 means rising edge. Opposite to your setting. So...

Regards,

Jing