2. Supported Hardware Platform

The following Nuclei Processor Cores based hardware platforms (more boards will be added in the future) are supported in this handbook.

2.1. RV-STAR Development Board

RV-STAR is a RISC-V development board based on GD32VF103 MCU. It provides on-board debugger, reset and wake-up user keys, RGB LED, USB OTG, and EXMC, Arduino, PMOD extension interfaces and other resources.

hw_fig1

Fig. 2.1 RV-STAR Development Board

2.1.1. Features and Specifications

Table 2.1 Features and Specifications of RV-STAR

Microcontroller

GD32VF103VBT6 (32-bit RISC-V Processor)

Core

Nuclei Bumblebee(RV32IMAC)

Frequency

108MHz

Memory

128KB Flash, 32KB SRAM

Operating Voltage

2.6 ~ 3.6V

Peripheral

Timer(Advanced 16-bit timer * 1, General 16-bit timer * 4)

U(S)ART * 5, I2C * 2, SPI * 3, CAN * 2, USBFS * 1, EXMC * 1

ADC * 2 (16 external channels), DAC * 2

Power Supply

5V USB or 5~9V External DC power (Arduino Vin)

Dimensions

66mm * 53.4mm

On-board Devices

and

Extension Interface

USB Type-C

Download and debug, serial communication

Micro USB

USB OTG

microSD card slot

(not soldered by default)

external SD card storage (SPI)

JTAG Interface

Separate MCU and debugger to make them work independently

PMOD * 2

I2C, SPI

Double row 2.54mm

female header

Arduino compatible (outside)

EXMC (inside)

User Key * 2

Reset, Wakeup

RGB LED * 1

Note

RV-STAR Development Board supports multiple power supply inputs, it allows multiple power supply to be connected at the same time when the jumper is connected properly. About the jumper connection, please refer to Jumper Section.

The Micro USB port supports bi-directional power supply, and the default is input. In the case of using Micro USB as the single power supply, please pull down the VBUS_OE# signal (MCU PD3 pin) to fully turn on the MOSFET (Q1) to ensure good power supply.

2.1.2. Extension Interface

Double row 2.54mm female header

The outside of P3~P6 is Arduino-Compatible interface, which can be directly connected to the relevant expansion boards with Arduino interface.

The corresponding MCU pins and function descriptions of the signals on the P3~P6 are listed below.

hw_fig2

Fig. 2.2 Double row 2.54mm female header

Table 2.2 Pin definition of P3

Type

Position

Name

MCU Pin

Default Function

Alternate Function

Arduino

2

PB10/SCL

47

PB10

I2C1_SCL, USART2_TX, TIMER1_CH2

4

PB11/SDA

48

PB11

I2C1_SDA, USART2_RX, TIMER1_CH3

6

NC

/

/

/

8

GND

/

GND

/

10

PA5

30

PA5

SPI0_SCK, ADC01_IN5, DAC_OUT1

12

PA6

31

PA6

SPI0_MISO, ADC01_IN06, TIMER2_CH0, TIMER0_BRKIN

14

PA7

32

PA7

SPI0_MOSI, ADC01_IN7, TIMER2_CH1, TIMER0_CH0_ON

16

PB9

96

PB9

TIMER3_CH3, I2C0_SDA, CAN0_TX

18

PB8

95

PB8

TIMER3_CH2, I2C0_SCL, CAN0_RX

20

PB6

92

PB6

I2C0_SCL, TIMER3_CH0, USART0_TX, CAN1_TX

EXMC

1

EXMC_A20

3

PE4

EXMC_A20

3

EXMC_A19

2

PE3

EXMC_A19

5

EXMC_A23

1

PE2

EXMC_A23

7

EXMC_A21

4

PE5

EXMC_A21

9

EXMC_A22

5

PE6

EXMC_A22

11

EXMC_NBL1

98

PE1

EXMC_NBL1

13

EXMC_NBL0

97

PE0

TIMER3_ETI, EXMC_NBL0

15

EXMC_NADV

93

PB7

I2C0_SDA, TIMER3_CH1, EXMC_NADV

17

EXMC_NE0

88

PD7

EXMC_NE0, USART1_CK

19

EXMC_NWAIT

87

PD6

EXMC_NWAIT, USART1_RX
Table 2.3 Pin definition of P4

Type

Position

Name

MCU Pin

Default Function

Alternate Function

Arduino

2

VIN

/

5~9V Power Supply

/

4

GND

/

GND

/

6

GND

/

GND

/

8

5V0

/

5V0 Power Output

/

10

3V3

/

3V3 Power Output

/

12

NRST

14

MCU Reset

/

14

3V3

/

3V3 Power Output

/

16

NC

/

/

/

EXMC

1

EXMC_D11

45

PE14

EXMC_D11, TIMER0_CH3

3

EXMC_D10

44

PE13

EXMC_D10, TIMER0_CH2

5

EXMC_D9

43

PE12

EXMC_D9, TIMER0_CH2_ON

7

EXMC_D8

42

PE11

EXMC_D8, TIMER0_CH1

9

EXMC_D7

41

PE10

EXMC_D7, TIMER0_CH1_ON

11

EXMC_D6

40

PE9

EXMC_D6, TIMER0_CH0

13

EXMC_D5

39

PE8

EXMC_D5, TIMER0_CH0_ON

15

EXMC_D4

38

PE7

EXMC_D4, TIMER0_ETI
Table 2.4 Pin definition of P5

Type

Position

Name

MCU Pin

Default Function

Alternate Function

Arduino

2

PC5

34

PC5

ADC01_IN15

4

PC4

33

PC4

ADC01_IN14

6

PC3

18

PC3

ADC01_IN13

8

PC2

17

PC2

ADC01_IN12

10

PC1

16

PC1

ADC01_IN11

12

PC0

15

PC0

ADC01_IN10

EXMC

1

EXMC_A17

59

PD12

EXMC_A17, TIMER3_CH0, USART2_RTS

3

EXMC_A16

58

PD11

EXMC_A16, USART2_CTS

5

EXMC_D15

57

PD10

EXMC_D15, USART2_CK

7

EXMC_D14

56

PD9

EXMC_D14, USART2_RX

9

EXMC_D13

55

PD8

EXMC_D13, USART2_TX

11

EXMC_D12

46

PE15

EXMC_D12, TIMER0_BRKIN
Table 2.5 Pin definition of P6

Type

Position

Name

MCU Pin

Default Function

Alternate Function

Arduino

2

PB5

91

PB5

I2C0_SMBA, SPI2_MOSI, I2S2_SD,

TIMER2_CH1, SPI0_MOSI, CAN1_RX

4

PB0

35

PB0

ADC01_IN8, TIMER2_CH2, TIMER0_CH1_ON

6

PB1

36

PB1

ADC01_IN9, TIMER2_CH3, TIMER0_CH2_ON

8

PA8

67

PA8

USART0_CK, TIMER0_CH0, CK_OUT0, USBFS_SOF

10

PC9

66

PC9

TIMER2_CH3

12

PC8

65

PC8

TIMER2_CH2

14

PC10

78

PC10

UART3_TX, USART2_TX, SPI2_SCK, I2S2_CK

16

PC11

79

PC11

UART3_RX, USART2_RX, SPI2_MISO

EXMC

1

EXMC_NWE

86

PD5

EXMC_NWE, USART1_TX

3

EXMC_NOE

85

PD4

EXMC_NOE, USART1_RTS

5

EXMC_D3

82

PD1

EXMC_D3, CAN0_TX, OSCOUT

7

EXMC_D2

81

PD0

EXMC_D2, CAN0_RX, OSCIN

9

EXMC_D1

62

PD15

EXMC_D1, TIMER3_CH3

11

EXMC_D0

61

PD14

EXMC_D0, TIMER3_CH2

13

EXMC_A18

60

PD13

EXMC_A18, TIMER3_CH1

15

*GND

/

*GND

GND, R31(0 Ohm) needed
PMOD

The RV-STAR Development Board provides two sets of standard PMOD interfaces, which can be conveniently connected to the relevant expansion boards with PMOD interface.

The corresponding MCU pins and function descriptions of the signals on the PMOD1, PMOD2 are listed below.

hw_fig3

Fig. 2.3 PMOD

Table 2.6 Pin definition of PMOD1

Type

Position

Name

MCU Pin

Default Function

Alternate Function

I2C

1

PC7

64

PC7

I2S2_MCK, TIMER2_CH1

2

PC6

63

PC6

I2S1_MCK, TIMER2_CH0

3

PB10/SCL

47

PB10

I2C1_SCL, USART2_TX, TIMER1_CH2

4

PB11/SDA

48

PB11

I2C1_SDA, USART2_RX, TIMER1_CH3

5

GND

/

GND

/

6

3V3

/

3V3 Power Output

/

7

PB4/NJTRST

90

NJTRST

SPI2_MISO, TIMER2_CH0, PB4, SPI0_MISO

8

PB2/BOOT1

37

PB2/BOOT1

Can be used as GPIO after boot

9

NC

/

/

/

10

NC

/

/

/

11

GND

/

GND

/

12

3V3

/

3V3 Power Output

/
Table 2.7 Pin definition of PMOD2

Type

Position

Name

MCU Pin

Default Function

Alternate Function

SPI

1

PA4

29

PA4

SPI0_NSS, USART1_CK, ADC01_IN4,

DAC_OUT0, SPI2_NSS, I2S2_WS

2

SD_MOSI

54

PB15

SPI1_MOSI, TIMER0_CH2_ON, I2S1_SD

3

SD_MISO

53

PB14

SPI1_MISO, USART2_RTS, TIMER0_CH1_ON

4

SD_SCLK

52

PB13

SPI1_SCK, USART2_CTS, TIMER0_CH0_ON,

I2S1_CK, CAN1_TX

5

GND

/

GND

/

6

3V3

/

3V3 Power Output

/

7

SD_CS

51

PB12

SPI1_NSS, I2C1_SMBA, USART2_CK,

TIMER0_BRKIN, I2S1_WS, CAN1_RX

8

PC13

7

PC13

TAMPER-RTC

9

NC

/

/

/

10

NC

/

/

/

11

GND

/

GND

/

12

3V3

/

3V3 Power Output

/

2.1.3. Jumper

The jumpers on RV-STAR are shown in the figure below, and their functions are described in the table below.

hw_fig4

Fig. 2.4 Jumpers on RV-STAR

Table 2.8 Function of Jumper

Jumper

Description

Options

Default

Function

P1

GND

2-1

O

Used to connect debugger and MCU. Contains standard

4-wire JTAG and 2-wire UART interface. Disconnect here

can separate MCU and debugger to make them work

independently. (The debugger can be used to debug other

devices, and the MCU can be debugged by other debuggers)

JTAG-TCK

4-3

O

JTAG-TDI

6-5

O

JTAG-TDO

8-7

O

JTAG-TMS

10-9

O

Reset

12-11

O

UART-TX

14-13

O

UART-RX

16-15

O

VDE-3V3

18-17

O

P2

BOOT0

(need to choose one)

4-6

L

O

Boot from flash

4-2

H

If choose this, the boot mode depends on BOOT1’s value

BOOT1

3-5

L

O

If BOOT0=1, boot from Bootloader

3-1

H

If BOOT0=1, boot from SRAM

P7

RTC Power Supply

(need to choose one)

2-1

3V3

O

From 3V3 power source on-board

2-3

BAT

From battery

External Battery needed

P10

5V Power Source

2-1

VIN

From Arduino Vin port

If choose this, Arduino Vin should be 5V0

2-3

VBUS

O

From USB Type-C

Note

Symbol “O” in the up table means connected.

2.1.4. On-board Debugger Driver

Install the Driver in Linux PC

For the Linux computer, the steps of installing driver for on-board debugger are as below:

  1. Prepare the PC. Use the VMware WorkStation to have Linux virtual machine installed, or just use the native Linux OS on your computer. It is recommended to use Ubuntu 16.04 or above version.

  2. Connect the PC and RV-STAR Development Board with the USB Type-C cable, make sure the USB is really be recognized by the Linux. For example, the USB symbol is highlighted in Ubuntu, as depicted in the figure below.

  3. Use the command to check the USB status.

    lsusb   // The example information displayed as below
...
Bus 001 Device 010: ID 0403:6010 Future Technology Devices International, Ltd FT2232xxxx

  4. Use the following command to set udev rules, to make this USB can be accessed by plugdev group.

    sudo vi /etc/udev/rules.d/99-openocd.rules
// Use vi command to edit the file, and add the following lines
SUBSYSTEM=="usb", ATTR{idVendor}=="0403",
ATTR{idProduct}=="6010", MODE="664", GROUP="plugdev"
SUBSYSTEM=="tty", ATTRS{idVendor}=="0403",
ATTRS{idProduct}=="6010", MODE="664", GROUP="plugdev"

  5. Use the following command to check if this USB is belong to plugdev group.

    ls /dev/ttyUSB*       // The example information showed as below after this command
/dev/ttyUSB0 /dev/ttyUSB1

ls -l /dev/ttyUSB1    // The example information showed as below after this command
crw-rw-r-- 1 root plugdev 188, 1 Nov 28 12:53 /dev/ttyUSB1

  6. Add your user name into the plugdev group.

    whoami
// Use above command to check your user name, assuming it is your_user_name
// Use below command to add your_user_name into plugdev group
sudo usermod -a -G plugdev your_user_name

  7. Double check if your user name is really belong to plugdev group.

    groups      // The example information showed as below after this command
... plugdev ...
// As long as you can see plugdev in groups, then means it is really belong to.
hw_fig5

Fig. 2.5 Ubuntu OS recognized USB

Install the Driver in Windows PC

For the Windows computer, the steps of installing driver for on-board debugger are as below:

  1. Connect the PC and RV-STAR Development Board with the USB Type-C cable, make sure the USB is really be recognized by the Windows.

  2. Download the on-board debugger’s Driver for Windows from this page, as depicted in the figure below.

  3. After downloading the package, double-click the HBird_Driver.exe.

  4. Since the on-board debugger has the functionality that “convert the UART to USB”, so if you have connected RV-STAR Development Board with PC and installed the driver successfully, then you will be able to see a USB Serial Port (e.g., COM8) show up in your Windows Device Manager.

hw_fig6

Fig. 2.6 Download the on-board debugger’s Driver for Windows

2.1.5. More Info

If you want to get more info about RV-STAR Development Board, GD32VF103 MCU and Nuclei Bumblebee Processor Core, please click the link in the following table to get the corresponding online docs.

Table 2.9 Online reference documents

Item

Online Docs

RV-STAR Development Board

Schematic

GD32VF103 MCU

User Manual

Datasheet

Nuclei Bumblebee Processor Core

ISA Manual