STM32F103C8 V/S GD32VF103Cx¶

These two MCU’s have totally different CORES, yet many of the PERIPHERALS are identical and both have Mecrisp Forth support, so this is a comparison page.

Note re GD32VF103Cx conditional branch range¶

Just a small correction: you mention that the conditional branches range is +/-2048 bytes, which is not exact. Since instructions can only be
aligned to 4 bytes, or 2 bytes for compressed instructions, the 12-bit offset actually encodes an offset that is in multiples of 2 bytes, which
is clever, so the range is +/-4096 bytes.

Mecrisp Support¶

MCU	Mecrisp Variant	Status	Tarball URL
STM32F103C8	Mecrisp-Stellaris	Stable	https://sourceforge.net/projects/mecrisp/files/mecrisp-stellaris-2.5.2.tar.gz/download
GD32VF103Cx	Mecrisp-Quintus	Experimental	https://sourceforge.net/projects/mecrisp/files/mecrisp-quintus-0.26-experimental.tar.gz/download

Note

Mecrisp-Quintus for the GD32VF103Cx is still experimental because the INTERRUPT support is not finalised.

Specifications¶

Parameter	STM32F103C8	GD32VF103Cx
Architecture	32-bit ARM Cortex M3	32 bit RISC-V
Operating Voltage	2.7V to 3.6V	2.6v to 3.6V
CPU Frequency	72 MHz	108 MHz
Number of GPIO pins	37	37 ?
Number of PWM pins	12	?
Analog input Pins	10 (12-bit)	?
ADC	1	2
DAC	0	1
SDIO	1	0
USART	3	3
UART	0	2
I2C	2	2
SPI	2	3
Can 2.0	1	2
Timers	4	7
Flash Memory	64kB stated, usually 128kB	128kB
RAM	20kB	32kB
Peripherals	33	46
Registers	466	1074
Bitfields	3503	7713

Peripherals¶

STM32F103C8	STM32F103C8 Peripheral	GD32VF103Cx	GD32VF103Cx Peripheral
.		ADC0
ADC1		ADC1
AFIO	Alternate function I/O	AFIO
BKP	Backup registers	BKP
CAN		CAN0
.		CAN1
CRC		CRC
.		DAC	12 bit digital to analog converter
DBG	Debug support	DBG
DMA1		DMA0
DMA2		DMA1
.		EXMC	External memory controller (EXMC)
EXTI	External interrupt/event controller	EXTI	External interrupt/event controller
FLASH		FMC	Flash memory controller (FMC)
GPIOA		GPIOA
GPIOB		GPIOB
GPIOC		GPIOC
GPIOD		GPIOD
I2C1		I2C0
I2C2		I2C1
IWDG	Independent watchdog	FWDGT	Free watchdog timer (FWDGT)
NVIC	Nested Vectored Interrupt Controller	ECLIC	Enhancement Core.Local Interrupt Controller (ECLIC)
PWR	Power control	PMU	Power management unit (PMU
RCC	Reset and clock control	RCU	Reset and clock unit (RCU
RTC	Real time clock	RTC
SDIO	Secure digital input/output interface	.
.		SPI0
SPI1		SPI1
SPI2		SPI2
TIM1	Advanced timer	TIMER0	Advanced-timers
TIM2	General purpose timer	TIMER1	General-purpose-timers
TIM3	General purpose timer	TIMER2	General-purpose-timers
TIM4	General purpose timer	TIMER3	General-purpose-timers
.		TIMER4	General-purpose-timers
.		TIMER5	Basic-timers
.		TIMER6	Basic-timers
USART1	Universal synchronous asynchronous receiver transmitter	USART0	Universal synchronous asynchronous receiver transmitter
USART2		USART1
USART3		USART2
.		UART3	Universal asynchronous receiver transmitter
.		UART4
USB	Universal serial bus full-speed device	USBFS_DEVICE	USB on the go full speed device
.		USBFS_GLOBAL	USB full speed global registers
.		USBFS_HOST	USB on the go full speed host
.		USBFS_PWRCLK	USB on the go full speed power and clock gating control
WWDG	Window watchdog	WWDGT	Window watchdog timer

ISA Comparisons¶

Description	RISC-V	Thumb
Conditional branches	12 bit	signed 8-bit (-256 to +256 bytes)
Register Load-Store Immediate		A base register Rn plus a 5-bit immediate
Peripherals reset to default	?	SYSRESETREQ

RISC-V Conditional branch workaround: invert the sense of the test and conditionally branch over an unconditional branch with more offset bits.

Premade Boards¶

RISC-V¶

Sipeed Longan Nano¶

RISC-V GD32VF103CBT6 Development Board

https://www.seeedstudio.com/Sipeed-Longan-Nano-RISC-V-GD32VF103CBT6-Development-Board-p-4205.html $4.90 USD

Wio Lite RISC-V (GD32VF103) - With ESP8266¶

Wio Lite RISC-V is a feather form factor RISC-V development board Based on GD32VF103, with the onboard ESP8266 Wio Core, it also features WiFi function.

https://www.seeedstudio.com/Wio-Lite-RISC-V-GD32VF103-p-4293.html $6.90 USD

Polos GD32V Alef¶

Polos GD32VF103 Alef Board – RISC-V MCU Board with 128KB Flash 32KB RAM

https://www.analoglamb.com/product/polos-gd32v-alef-board-risc-v-mcu-board/ $2.99 USD

STM32F103C8¶

Blue Pill¶

Available everywhere on the Internet around $2USD