PM0212

Programming STM8 Flash microcontrollers

Doc ID 022351 Rev 2

17/22

4.5.2

How to program the option bytes

The option bytes are stored only once.

On STM8TL5xxx devices, the option bytes can be modified only in ICP/SWIM mode with

OPT bit of the FLASH_CR2 register set to ‘1’ (refer to the description of FLASH_CR2

register in the reference manual).

4.6

Memory access versus programming method

Table 5 gives a description of possible accesses from the core to memory areas according

to the programming method.

Table 5.

Memory access versus programming method

Mode

ROP

Memory Area

Access

User, IAP

Readout

protection

enabled

Interrupt vectors except for TRAP

TRAP

R/W/E

Proprietary code area (PCODE)

R/E

User boot code area (UBC)

R/E

Main program

R/W/E

Data EEPROM area (DATA)

Option bytes

R

Readout

protection

disabled

Interrupt vectors except for TRAP

R/W(2)/E

TRAP

R/W/E

Proprietary code area (PCODE)

User boot code area (UBC)

Main program

R/W/E(7)

Data EEPROM area (DATA)

R/W(3)

Option bytes

R