Application Overview

Application Data Flow

Memory Footprint Details

Read-Only Data

Name	Size	Location	Notes
face_detector_data	151 KB	.rodata	FLASH xSPI2 8b
face_landmark_data	470 KB	.rodata	FLASH xSPI2 8b

Read-Write Data

Name	Size	Location	Notes
lcd_bg_buffer	3375 KB	.psram_bss	PSRAM / (800x480x3) x 3 / RGB888
lcd_fg_buffer	1500 KB	.psram_bss	PSRAM / (800x480x2) x 2 / ARGB4444
nn_input_buffers	96 KB	.bss	SRAM / (128x128x3) x 2 / RGB888
fl_input_buffers	216 KB	.bss	SRAM / (192x192x3) x 2 / RGB888
activations	720 KB	0x34200000	NPURAMS
threads stacks	18 KB	.bss	SRAM

DCMIPP and ISP

DCMIPP Overview

• Pipe 1 is enabled using CMW_CAMERA_Start(DCMIPP_PIPE1, *ptr_dst, CAMERA_MODE_CONTINUOUS); to continuously transmit images from IMX335 to the DISPLAY_BUFFER_NB buffered lcd_bg_buffer[]. Note that ptr_dst will be updated at the pipe1 frame_event.
• Pipe 2 is enabled using CMW_CAMERA_Start(DCMIPP_PIPE2, *ptr_dst, CAMERA_MODE_CONTINUOUS); to continuously transmit images from IMX335 to the double buffered nn_input_buffers[]. Note that ptr_dst will be updated at the pipe2 frame_event. This allows dropping the previous frame if the buffer is still in use by the nn thread.
• For each capture, the ISP configuration is updated to enhance the image quality depending on the illumination conditions. It is initialized through ISP_Init and then executed with ISP_BackgroundProcess.

For more details on DCMIPP, see the Digital Camera Interface Pixel Pipeline (DCMIPP) section in the STM32N6 Reference Manual.