Welcome to the Edge Vision SoC GitHub repo. Efinix offers an RISC-V SoC framework targeted for edge vision applications, namely Edge Vision SoC (EVSoC) framework. This site provides source codes, example designs, and supporting materials of the EVSoC framework.

• Overview
• Image Signal Processing Example Design
• Dual-Camera Example Design
• Hardware and Software Setup
• Documentation
• Videos
• Frequently Asked Questions

Note:

• The main branch contains new version of EVSoC, which is based on user configurable Efinix Sapphire RISC-V SoC.
• A branch named evsoc_ruby is created for the older version of EVSoC, which is based on Efinix Ruby Vision RISC-V SoC.

Key features:

• Modular building blocks to facilitate different combinations of system design architecture
• Established data transfer flow between main memory and different building blocks through Direct Memory Access (DMA)
• Ready-to-deploy domain-specific I/O peripherals and interfaces (SW drivers, HW controllers, pre- and post-processing blocks are provided)
• Highly flexible HW/SW co-design is feasible (RISC-V performs control & compute, HW accelerator for time-critical computations)
• Enable quick porting of users' design for edge AI and vision solutions

Building blocks to facilitate ease of modification to suit for various system architecture requirements:

• RISC-V SoC
• DMA Controller
• Camera
• Display
• Hardware Accelerator

ISP example design demonstrates a use case on the EVSoC framework, specifically, hardware/software co-design for video processing. Additionally, the design shows how user can control the FPGA hardware using software, that is, user can enable different hardware acceleration functions by changing firmware in the RISC-V processor.

This example presents these concepts in the context of video filtering functions; however, user can use the same design with own hardware accelerator block instead of the provided filtering functions. The design helps user explore accelerating computationally intensive functions in hardware and using RISC-V software to control that acceleration as well as to perform computations that are inherently sequential or require flexibility.

List of implemented ISP algorithms (available for both SW functions and HW modules):

• RGB to grayscale conversion
• Sobel edge detection
• Binary dilation
• Binary erosion

Multi-camera vision systems are vital for a wide-range of applications such as video surveillance, security system, robotics, automotive and drone. The benefits of multi-camera vision system over single-camera setup include:

• Resolve occlusion problem
• Provide wider area coverage
• Produce more accurate geometric understanding

EVSoC presents a dual-camera example design that provides a flexible hardware accelerator socket for processing frame data from multiple camera sources based on the targeted applications.

List of implemented HW accelerator mode - Merging:

• Merge two horizontally half cropped frame from two camera sources by left and right
• Merge a downscaled overlay from one camera source on top of the frame data from another camera source

List of implemented HW accelerator mode - Processing:

• Cam source 1 – Passthrough (RGB or Grayscale); Cam source 2 – Passthrough (RGB or Grayscale)
• Cam source 1 – Passthrough (RGB or Grayscale); Cam source 2 – Processed (Sobel)
• Cam source 1 – Processed (Sobel); Cam source 2 – Passthrough (RGB or Grayscale)
• Cam source 1 – Processed (Sobel); Cam source 2 – Processed (Sobel)

The example designs are implemented on:

• Trion® T120 BGA324 Development Kit
• Trion® T120 BGA576 Development Kit
• Titanium® Ti60 F225 Development Kit

Efinity® IDE is required for project compilation and bitstream generation, whereas RISC-V SDK (includes Eclipse, OpenOCD Debugger, etc) is used to manage RISC-V software projects and for debugging purposes.

Please refer to EVSoC User Guide to get started.

• Efinity® IDE v2021.2.323.2.18
• RISC-V SDK v1.4

• EVSoC User Guide
• Sapphire RISC-V SoC Datasheet
• Ruby Vision RISC-V SoC Datasheet
• Trion T120 BGA324 Development Kit User Guide
• Trion T120 BGA576 Development Kit User Guide
• Titanium Ti60 F225 Development Kit User Guide

• Edge Vision SoC Solution
• ISP Example Design Tutorial - Demonstration
• ISP Example Design Tutorial - Firmware
• ISP Example Design Tutorial - RTL Design
• ISP Example Design Tutorial - Flash Memory Read & Write
• Dual-Camera Example Design Tutorial
• Ti60 F225 Demonstration

1. Where are the HW/RTL and SW/firmware source files located?

   The top-level RTL file is named edge_vision_soc.v, located in individual project folder. The rest of the RTL files are placed in source directory, which are organized according to respective building block. On the other hand, the main firmware file is named main.c, located in embedded_sw/SapphireSoc/software/evsoc/*/src directory, where other related drivers are provided in the same folder as well.

   Below depicts the directory structure of EVSoC framework:

   ├── T120F324_1280_720
   │   ├── embedded_sw
   │   │   └── SapphireSoc
   │   │       └── software
   │   │           └── evsoc
   │   ├── ip
   │   ├── sim
   │   └── source
   ├── T120F324_1280_720_dualCam
   │   ├── embedded_sw
   │   │   └── SapphireSoc
   │   │       └── software
   │   │           └── evsoc
   │   ├── ip
   │   └── source
   ├── T120F324_640_480
   │   ├── embedded_sw
   │   │   └── SapphireSoc
   │   │       └── software
   │   │           └── evsoc
   │   ├── ip
   │   ├── sim
   │   └── source
   ├── T120F576_1280_720
   │   ├── embedded_sw
   │   │   └── SapphireSoc
   │   │       └── software
   │   │           └── evsoc
   │   ├── ip
   │   ├── sim
   │   └── source
   ├── T120F576_1280_720_dualCam
   │   ├── embedded_sw
   │   │   └── SapphireSoc
   │   │       └── software
   │   │           └── evsoc
   │   ├── ip
   │   └── source
   ├── T120F576_640_480
   │   ├── embedded_sw
   │   │   └── SapphireSoc
   │   │       └── software
   │   │           └── evsoc
   │   ├── ip
   │   ├── sim
   │   └── source
   └── Ti60F225_dsi
       ├── embedded_sw
       │   └── SapphireSoc
       │       └── software
       │           └── evsoc
       ├── ip
       ├── sim
       └── source
   

   Note: Source files for Efinix soft-IP(s) are to be generated using IP Manager in Efinity® IDE, where IP settings files are provided in ip directory in respective project folder. Please refer to EVSoC User Guide for more detail.

2. How much is the resource consumption for EVSoC framework?

   Below are the resource utilization tables compiled for Efinix Trion® T120F324 device using Efinity® IDE v2021.2.

   Resource utilization for ISP example design (640x480 resolution):

   Building Block	LE	FF	ADD	LUT	MEM (M5K)	MULT
   Edge Vision SoC (Total)	33446	16372	2543	24356	192	4
   RISC-V SoC	-	7156	534	6400	54	4
   DMA Controller	-	7553	1106	15967	92	0
   Camera	-	764	691	1035	22	0
   Display	-	171	13	219	10	0
   Hardware Accelerator	-	616	187	577	14	0

   Resource utilization for ISP example design (1280x720 resolution):

   Building Block	LE	FF	ADD	LUT	MEM (M5K)	MULT
   Edge Vision SoC (Total)	34633	16404	2543	23638	204	4
   RISC-V SoC	-	7156	534	6354	54	4
   DMA Controller	-	7570	1106	15250	92	0
   Camera	-	765	691	1055	22	0
   Display	-	172	13	214	10	0
   Hardware Accelerator	-	629	187	595	26	0

   Resource utilization for dual-camera example design (1280x720 resolution):

   Building Block	LE	FF	ADD	LUT	MEM (M5K)	MULT
   Edge Vision SoC (Total)	37871	18198	3302	26034	344	4
   RISC-V SoC	-	7127	534	6358	54	4
   DMA Controller	-	8382	1156	16290	195	0
   Camera (x2)	-	1530	1382	2061	44	0
   Display	-	172	13	237	10	0
   Hardware Accelerator	-	819	205	894	41	0

   Below are the resource utilization tables compiled for Efinix Titanium® Ti60F225 device using Efinity® IDE v2021.2.

   Resource utilization for ISP example design:

   Building Block	XLR	FF	ADD	LUT	MEM (M10K)	DSP
   Edge Vision SoC (Total)	34289	17653	2376	23941	206	4
   RISC-V SoC	-	6790	508	5788	49	4
   DMA Controller	-	4763	683	6578	53	0
   CSI-2 RX Controller Core	-	835	41	2124	15	0
   DSI TX Controller Core	-	1486	93	4039	17	0
   HyperRAM Controller Core	-	1153	194	2186	13	0
   Camera	-	776	643	996	11	0
   Display	-	341	15	598	27	0
   Hardware Accelerator	-	620	187	594	8	0

   Note: Resource values may vary from compile-to-compile due to PnR and updates in RTL. The presented tables are served as reference purposes.

3. How to check if the hardware and software setup for ISP example design is done correctly?

   After setting up the hardware and software accordingly (refer to EVSoC User Guide for the detail), user is to program the hardware bitstream (using Efinity Programmer) and software binary (using Eclipse software) to the targeted development kit.

   User is expected to see colour bar on display, which lasts for a few seconds. This indicates the display, RISC-V, and DMA are running correctly. If evsoc_ispExample or evsoc_ispExample_demo* software apps is used, user is expected to see video streaming of camera captured output (default mode) on display after the colour bar. This shows the camera is setup correctly too.

   In the case of the above expected outputs are not observed, user is to check on the board, camera, display, software setup, etc., with reference to EVSoC User Guide.

4. How to modify camera input resolution from MIPI interface?

   For HW, modify MIPI_FRAME_WIDTH and MIPI_FRAME_HEIGHT parameter values in edge_vision_soc.v accordingly. For SW, note to ensure the same set of values are set in camera SW driver (PiCamDriver.c) under PiCam_init() function, for example:

   PiCam_Output_Size(1920, 1080); 
   

   Refer to Raspberry Pi Camera Module v2 Datasheet for more detail about camera setting.

5. Why is after enabling Sobel operation (either HW or SW mode) in the firmware, display shows only black with scatter white lines/dots?

   There are several potential factors that contribute to this, please try out the following adjustments:

   (a) Place an object with high colour contrast such as calendar, brochure, name card, etc., in front of the camera and observe the detected edge outlines.

   (b) Modify the Sobel threshold value by changing the line:

   write_u32(100, EXAMPLE_AXI4_SLV + EXAMPLE_AXI4_SLV_REG0_OFFSET);
   

   in firmware (main.c). The Sobel threshold value is to be adjusted based on the lighting condition where the camera operates at.

6. Why is zooming effect observed on ISP example design, especially for 640x480 resolution?

   This is due to the default setup performs cropping on the incoming 1920x1080 resolution MIPI camera frames to a smaller size eg., 640x480 resolution, prior to further processing. To perform resizing with scaling method, modify the CROP_SCALE parameter that is passed to cam_picam_v2 instance at edge_vision_soc.v.

7. Why are captured frames not of central view of the camera?

   This is due to the default setup for cropping is with X- and Y-offsets (0,0). To adjust the cropping offsets, modify the X_START and Y_START parameter values that are passed to crop instance at cam_picam_v2.v.

8. What is the mechanism used to configure and trigger an DMA transfer?

   RISC-V firmware is used to configure DMA controller through APB3 slave port. SW driver for DMA controller (dmasg.h) is in embedded_sw/SapphireSoc/software/standalone/driver directory.

9. How does RISC-V detect completion of a triggered DMA transfer?

   User can make use of polling or interrupt mode in RISC-V firmware to detect the completion of an DMA transfer. In the ISP example design, DMA completion checking with polling mode is demonstrated in the firmware (main.c).

   The following presents an example for converting the default self-restart display DMA channel to make use of interrupt mode to indicate DMA transfer completion of single video frame. In main.c, make these changes to the Trigger Display section:

   //SELECT start address of to be displayed data accordingly.
   dmasg_input_memory(DMASG_BASE, DMASG_DISPLAY_MM2S_CHANNEL, CAM_START_ADDR, 16);
   //dmasg_input_memory(DMASG_BASE, DMASG_DISPLAY_MM2S_CHANNEL, GRAYSCALE_START_ADDR, 16);
   //dmasg_input_memory(DMASG_BASE, DMASG_DISPLAY_MM2S_CHANNEL, SOBEL_START_ADDR, 16);
   dmasg_output_stream(DMASG_BASE, DMASG_DISPLAY_MM2S_CHANNEL, DMASG_DISPLAY_MM2S_PORT, 0, 0, 1);
   
   //Add interrupt config command
   dmasg_interrupt_config(DMASG_BASE, DMASG_DISPLAY_MM2S_CHANNEL, DMASG_CHANNEL_INTERRUPT_CHANNEL_COMPLETION_MASK);
   dmasg_direct_start(DMASG_BASE, DMASG_DISPLAY_MM2S_CHANNEL, (IMG_WIDTH*IMG_HEIGHT)*4, 0);
   
   //Indicate that the display DMA channel is active
   display_mm2s_active = 1;
   

   In dmasg_config.h, go to the externalInterrupt() function and set up the interrupt service subroutine accordingly.

   void trigger_next_display_dma () {
      dmasg_input_memory(DMASG_BASE, DMASG_DISPLAY_MM2S_CHANNEL, CAM_START_ADDR, 16);
      dmasg_output_stream(DMASG_BASE, DMASG_DISPLAY_MM2S_CHANNEL, DMASG_DISPLAY_MM2S_PORT, 0, 0, 1);
      dmasg_interrupt_config(DMASG_BASE, DMASG_DISPLAY_MM2S_CHANNEL, DMASG_CHANNEL_INTERRUPT_CHANNEL_COMPLETION_MASK);
      dmasg_direct_start(DMASG_BASE, DMASG_DISPLAY_MM2S_CHANNEL, (IMG_WIDTH*IMG_HEIGHT)*4, 0);
   }
   
   void externalInterrupt(){
     uint32_t claim;
     //While there is pending interrupts
     while(claim = plic_claim(BSP_PLIC, BSP_PLIC_CPU_0)){
        switch(claim){
           case PLIC_DMASG_CHANNEL:
              if(display_mm2s_active && !(dmasg_busy(DMASG_BASE, DMASG_DISPLAY_MM2S_CHANNEL))) {
                 trigger_next_display_dma();
              }
              break;
           default: crash(); break;
        }
        plic_release(BSP_PLIC, BSP_PLIC_CPU_0, claim); //unmask the claimed interrupt
     }
   }
   

10. How to customize RISC-V firmware for different HW/SW scenarios available in the ISP example design?

    Please refer to Customizing the Firmware section in EVSoC User Guide for the detail.

11. How to replace the example ISP hardware accelerator core with user custom accelerator?

    Please refer to Using Your Own Hardware Accelerator section in EVSoC User Guide for the detail.

12. How to obtain processing frame rate of a specific scenario in the ISP example design?

    Software app evsoc_ispExample_timestamp is provided in embedded_sw/SapphireSoc/software/evsoc directory for this purpose. MIPI camera input frame rate is determined by a hardware counter in camera building block, whereas software timestamp method is used for the processing frame rate profiling purposes. Formulae used to compute frames/second and seconds/frame are provided in the main.c.