Duo256M

The Milk-V Duo 256M is an upgraded version of Duo with a memory boost to 256M, catering to applications demanding larger memory capacities. It features the SG2002 computing series chip, elevating computational power to 1.0TOPS@INT8. It enables seamless switching between RISC-V/ARM architectures and supports simultaneous operation of dual systems. Additionally, it includes an array of rich GPIO interfaces such as SPI, UART, suitable for a wide range of hardware development in edge intelligent monitoring, including IP cameras, smart peephole locks, visual doorbells, and more.

Introduction of SG2002

SG2002 is a high-performance, low-power chip designed for various product fields such as edge intelligent surveillance IP cameras, smart door locks, visual doorbells, and home intelligence. It integrates H.264 video compression and decoding, H.265 video compression encoding, and ISP capabilities. It supports multiple image enhancement and correction algorithms such as HDR wide dynamic range, 3D noise reduction, defogging, and lens distortion correction, providing customers with professional-grade video image quality.

The chip also incorporates a self-developed TPU, delivering 1.0 TOPS of computing power under 8-bit integer operations. The specially designed TPU scheduling engine efficiently provides high-bandwidth data flow for all tensor processing unit cores. Additionally, it offers users a powerful deep learning model compiler and software SDK development kit. Leading deep learning frameworks like Caffe and Tensorflow can be easily ported to its platform. Furthermore, it includes security boot, secure updates, and encryption, providing a series of security solutions from development, mass production, to product applications.

The chip integrates an 8-bit MCU subsystem, replacing the typical external MCU to achieve cost-saving and power efficiency goals.

SG2002 Public Preliminary Datasheet

We have open sourced the Public Preliminary Datasheet and TRM of SG2002 to GitHub. please check it out.

Buy the SG2002 Chips

Milk-V is the Authorised Global Distributor of the SG2002 chips. You can buy samples of the SG2002 chip from our distributor online store directly. For volume order, please contact Milk-V Sales Team for the qoutation.

Getting Started

Installing the system

Please refer to the Start Up section.

USB Network Usage

Please refer to the Setup section.

Duo256M GPIO Pinout

GPIO pin mapping

GROUP	ADDR	PORT	CHIP	NUM	NAME	START
gpio0	gpio@03020000	porta	gpiochip0	480-511	XGPIOA	480 - XGPIOA[0]
gpio1	gpio@03021000	portb	gpiochip1	448-479	XGPIOB	448 - XGPIOB[0]
gpio2	gpio@03022000	portc	gpiochip2	416-447	XGPIOC	416 - XGPIOC[0]
gpio3	gpio@03023000	portd	gpiochip3	384-415
gpio4	gpio@05021000	porte	gpiochip4	352-383	PWR_GPIO	352 - PWR_GPIO[0]

GPIO Pinout

JTAG	SPI	SPI-NOR	SD	PWM	I2C	UART	NUM	SG2002	NAME	PIN	PIN	NAME	SG2002	NUM	ADC	SPI-NOR	SPI-NAND	EMMC
JTAG_TDI						UART1/2_TX	508	XGPIOA[28]	GP0	1	40	VBUS(5V)
JTAG_TDO						UART1/2_RX	509	XGPIOA[29]	GP1	2	39	VSYS(5V)
									GND	3	38	GND
JTAG_TMS				PWM7		UART1_TX	499	XGPIOA[19]	GP2	4	37	3V3_EN
JTAG_TCK				PWM6		UART1_RX	498	XGPIOA[18]	GP3	5	36	3V3(OUT)
		NOR1_HOLD	SD1_D2	PWM5	I2C1_SCL	UART2/3_TX	371	PWR_GPIO[19]	GP4	6	35	Boot-Switch
		NOR1_WP	SD1_D1	PWM6	I2C1_SDA	UART2/3_RX	372	PWR_GPIO[20]	GP5	7	34	Audio-Out
									GND	8	33	GND
	SPI2_SCK	NOR1_SCK	SD1_CLK	PWM9	I2C3_SDA		375	PWR_GPIO[23]	GP6	9	32	GP27	XGPIOB[6]	454
	SPI2_SDO	NOR1_MOSI	SD1_CMD	PWM8	I2C3_SCL		374	PWR_GPIO[22]	GP7	10	31	GP26	XGPIOB[3]	451	ADC1(1.8V)
	SPI2_SDI	NOR1_MISO	SD1_D0	PMW7	I2C1_SDA	UART3_RTS	373	PWR_GPIO[21]	GP8	11	30	RUN
	SPI2_CS	NOR1_CS	SD1_D3	PWM4	I2C1_SCL	UART3_CTS	370	PWR_GPIO[18]	GP9	12	29	GP22	PWR_GPIO[4]	356
									GND	13	28	GND
				PWM10	I2C2_SDA		430	XGPIOC[14]	GP10	14	27	GP21	XGPIOA[26]	506		NOR_HOLD	NAND_HOLD	EMMC_DAT2
				PWM11	I2C2_SCL		431	XGPIOC[15]	GP11	15	26	GP20	XGPIOA[27]	507		NOR_WP	NAND_WP	EMMC_DAT3
				PWM4		UART0/1_TX	496	XGPIOA[16]	GP12	16	25	GP19	XGPIOA[25]	505		NOR_MOSI	NAND_MOSI	EMMC_DAT0
				PWM5		UART0/1_RX	497	XGPIOA[17]	GP13	17	24	GP18	XGPIOA[22]	502		NOR_SCK	NAND_SCK	EMMC_CLK
									GND	18	23	GND
							494	XGPIOA[14]	GP14	19	22	GP17	XGPIOA[24]	504		NOR_CS	NAND_CS	EMMC_DAT1
							495	XGPIOA[15]	GP15	20	21	GP16	XGPIOA[23]	503		NOR_MISO	NAND_MISO	EMMC_CMD
							354	PWR_GPIO[2]		LED

The logic level of GP26 and GP27 pins is 1.8V, and the logic level of other GPIO pins is 3.3V logic level.

Camera interface

Duo256M camera uses a 16-pin connector with a distance of 0.5 mm, which can be directly used with the CAM-GC2083 camera head.

Connector FPC Definition

J1	Description
1	GND
2	MIPI0_DN0
3	MIPI0_DP0
4	GND
5	MIPI0_DN1
6	MIPI0_DP1
7	GND
8	MIPI0_CKN
9	MIPI0_CKP
10	GND
11	SENSOR_RSTN (1.8V)
12	SENSOR_CLK (1.8V)
13	I2C2_SCL (1.8V)
14	I2C2_SDA (1.8V)
15
16	3V3

Duo256M User Guide

UART Serial Console

Duo256M has a reserved UART debug serial port, which can be used to view the system startup log, or to log in to the console after the system starts and execute some terminal commands.

USB-TTL Serial Cable

The serial port level of Duo series is 3.3V.

The pin definitions of common USB to TTL serial cables are as follows:

Connection

Connect the USB to TTL serial cable as shown below, leaving the red wire unconnected.

Milk-V Duo256M	<--->	USB to TTL
TX (pin 16)	<--->	White wire
RX (pin 17)	<--->	Green wire
GND (pin 18)	<--->	Black wire

The default serial port parameters of Duo256M are as follows:

baudrate: 115200
data bit: 8
stop bit: 1
parity  : none
flow control: none

RISC-V and ARM switching

The large core of Duo256M can choose to use RISC-V or ARM processor. The RISC-V core is used by default. You can switch to the ARM core by shorting physical pin 35 (Boot-Switch) and GND. If you find that Duo256M cannot start normally during use, please first check whether the core currently used is consistent with the firmware used.

If the debug serial port is connected, you can see in the first line of the boot log that starting with C means starting from the RISC-V core, and starting with B means starting from the ARM core.

• RISC-V:

  C.SCS/0/0.C.SCS/0/0.WD.URPL.USBI.USBW
• ARM:

  B.SCS/0/0.WD.URPL.B.SCS/0/0.WD.URPL.USBI.USBW

Hardware Docs

Others

https://github.com/milkv-duo/duo-files/tree/main/duo-256M