Part Number:CC3220
Hello,
I have ported the camera application form the CC3200 SDK to the CC3220 SDK but have had some issues getting it to work perfectly in JPEG mode. I have the same MT9D111 camera which was used in the original project and have become very familiar with it throughout the porting process.
In the original TI example project, the CC3220 camera peripheral is setup to output an Xclk clock signal to the camera sensor with a frequency of 24 MHz. This is then divided down in the camera such that it outputs a pixel clock of around 4 MHz which is used to latch data into the camera peripheral. Unfortunately, the camera peripheral seems to be incapable of reading in data when the pixel clock is this high. In fact, the TI datasheet claims that the max input pixel clock to the CC3220 camera peripheral is 2 MHz. However, the code I ported over was an exact copy form the CC3200 project. Therefore, I am a little confused why the image capture does not work properly. Below I posted two photos that I captured with the camera. The corrupted one was with the project's default clock settings (Xclk = 24 MHz, Pclk = 4 MHz) and the other picture was with a Xclk of 8 MHz and a Pclk of 1.5 MHz.
In fact, I was even able to narrow down the absolute maximum pixel clock before the image is corrupted. With Xclk = 9 MHz, the Pclk goes to 1.61 MHz and the camera peripheral returns a corrupted image as shown below. Changing the pixel clock from 1.5 to 1.6 MHz seems to break everything.
Does anyone have any insight into this issue? I was thinking that this may be a problem with the DMA not being able to clear the camera peripheral's FIFO fast enough. Alternatively, the camera peripheral may fail to read the data when the latching pixel clock is too fast; however, the setup and hold time specifications listed in the data sheet would suggest this is not the case. Ideally I can run the Xclk and Pclk as fast as possible to get the highest frame rate, but with the current limitations, I have been getting around 2 FPS which is not ideal. Any feedback would be appreciated!
Thanks,
Nicholas