ST STM8

The STM8 family from STMicroelectronics is designed for cost-sensitive embedded applications, offering a good balance of performance, low power consumption, and integrated peripherals. It features a robust Harvard architecture, flash memory, multiple communication interfaces (such as UART, SPI, and I²C), and is widely used in industrial, automotive, and consumer electronics systems.

Supported devices

Refer to the STM8AS device list and the STM8L device list for a full list of all supported STM8 family devices, their corresponding names and connection diagrams.

Target interfaces

This device supports only 'Single Wire Interface Module' (SWIM).

Interface	J-Link support	Flasher support
SWIM

Memory blocks

Flash bank	Base address	J-Link support	Flasher support	Loader
				Name	Bank size
Data EEPROM	0x4000			Default	up to 2kB
Option bytes	0x4800			Default	128 Bytes
Program memory	0x8000			Default	up to 128kB

Limitations

Depending on the used tool chain, the Option bytes area may not be fully populated.

This can be fixed using a small Python script: from intelhex import IntelHex

ih = IntelHex()
ih.loadhex('infile.hex')
ih[0x4802] = ih[0x4801] ^ 0xFF # NOPT1
ih[0x4804] = ih[0x4803] ^ 0xFF # NOPT2
ih[0x4806] = ih[0x4805] ^ 0xFF # NOPT3
ih[0x4808] = ih[0x4807] ^ 0xFF # NOPT4
ih[0x480A] = ih[0x4809] ^ 0xFF # NOPT5
ih[0x480C] = ih[0x480B] ^ 0xFF # NOPT6
ih[0x480E] = ih[0x480D] ^ 0xFF # NOPT7
ih.tofile('outfile.hex', format='hex')

STM8 Adapter

SEGGER offers an adapter with standard connectors for STM8 evaluation boards.

Please note that without the STM8 adapter you have to connect the SWIM line to TCK and via a 1k resistor to PIN17.