Description

RV-Debugger-BL702 is an opensource project that implement a JTAG+UART debugger with BL702C-A0.

BL702 is highly integrated BLE and Zigbee combo chipset for IoT applications, contains 32-bit RISC-V CPU with FPU, frequency up to 144MHz, with 132KB RAM and 192 KB ROM, 1Kb eFuse, 512KB embedded Flash, USB2.0 FS device interface, and many other features.

The firmware implement is inspired by open-ec, implement by Sipeed teams and community developers.

The firmware emulate an FT2232D device, defaultly implement an JTAG+UART debugger, and can be implement as a Dual-Serial Port debugger, a bluetooth debugger, etc.

Community Forum: bbs.sipeed.com

Hardware

Offical Board

Sipeed RV-Debugger-Plus (BL702C-A0)

Purchase link: taobao.com/xxx

Schematic: BL702_USB2JTAG_3610_sch.pdf

Assembly: BL702_USB2JTAG_3610_asm.pdf

(LED0 is the led close to edge, indicate for RX)

Third-party Hardware

TODO

Firmware

Flash Tutorial

Press "boot" button then plug usb cable, and you will see "CDC Virtual ComPort" in device manager , remember the com number.

The flash tool is in tools/bflb_flash_tool directory, and input the command (replace port number and firmware name):

Windows:
.\bflb_mcu_tool.exe --chipname=bl702 --port=COM9 --xtal=32M --firmware="main.bin"
Linux:
./bflb_mcu_tool --chipname=bl702 --port=/dev/ttyACM0 --xtal=32M --firmware="main.bin"

tools\bflb_flash_tool> .\bflb_mcu_tool.exe --chipname=bl702 --port=COM9 --xtal=32M --firmware="main.bin"
[22:07:28.296] - ==================================================
[22:07:28.296] - Chip name is bl702
[22:07:28.297] - Serial port is COM9
[22:07:28.299] - Baudrate is 115200
[22:07:28.299] - Firmware is main.bin
[22:07:28.300] - Default flash clock is 72M
[22:07:28.300] - Default pll clock is 144M
[22:07:28.311] - ==================================================
[22:07:28.483] - Update flash cfg finished
[22:07:28.500] - EFUSE_CFG
[22:07:28.500] - BOOTHEADER_CFG
......
[22:07:31.274] - Load 53856/53856 {"progress":100}
[22:07:31.274] - Write check
[22:07:31.274] - Flash load time cost(ms): 267.942626953125
[22:07:31.275] - Finished
[22:07:31.276] - Sha caled by host: 825d198270c2cf509acda8f8e0830751c532da802060c324a4479e1fe599ae1f
[22:07:31.276] - xip mode Verify
[22:07:31.288] - Read Sha256/53856
[22:07:31.288] - Flash xip readsha time cost(ms): 12.508056640625
[22:07:31.288] - Finished
[22:07:31.288] - Sha caled by dev: 825d198270c2cf509acda8f8e0830751c532da802060c324a4479e1fe599ae1f
[22:07:31.288] - Verify success
[22:07:31.289] - Program Finished
[22:07:31.289] - All time cost(ms): 2220.2548828125
[22:07:31.390] - [All Success]

Another GUI flash tool is BouffaloLabDevCube:

usb2uartjtag (default)

Support JTAG+UART function

UART support baudrate below 2Mbps, and 3Mbps, and some experimental baudrate (stability is not guaranteed):

12M, 9.6M, 8M, 6.4M, 6M, 4.8M, 4M, 3.2M
we remap baudrate in 10000~12000 to (baud-10000)*10000
for example, 11200bps -> 12Mbps

LED0 for RX indication, LED1 for TX indication.

JTAG function is verified for :

RV32 Xuantie E906/E907
RV64 Xuantie C906
Gowin FPGA GW1N-1, GW1NS-4C. (need enable GOWIN_INT_FLASH_QUIRK)

usb2dualuart

TODO.

Project Structure

RV-Debugger-BL702
├── bsp
│   ├── board
│   │   └── bl702_debugger
│   └── bsp_common
│       └── platform
├── common
│   ├── device
│   ├── libc
│   ├── list
│   ├── memheap
│   ├── misc
│   ├── partition
│   ├── ring_buffer
│   └── soft_crc
├── components
│   ├── shell
│   └── usb_stack
├── drivers
│   └── bl702_driver
├── examples
│   └── usb
│       ├── usb2uartjtag
│       └── usb2dualuart
├── out
├── tools
│   ├── bflb_flash_tool
│   ├── cdk_flashloader
│   ├── cmake
│   └── openocd
└── hardware

BL SDK usage tutorial refer to http://bouffalolab.gitee.io/bl_mcu_sdk/

Develop Guide

Build

just "make"

Code Explanation

the main file is:

examples/usb/usb2uartjtag:
├── main.c
├── uart_interface.c
├── jtag_process.c
└── io_cfg.h         //main io cfg, another file is pinmux_config.h in bsp/board/bl702_debugger
components/usb_stack/class/vendor:
└── usbd_ftdi.c      //all FTDI vendor request process, like baudrate set, dtr/rts set, Latency_Timer