Option bytes
Option bytes contain configurations for device hardware features as well as the memory
protection of the device. They are stored in a dedicated block of the memory. Except for the
ROP (read-out protection) byte, each option byte has to be stored twice, in a regular form
(OPTx) and a complemented one (NOPTx) for redundancy.
Option bytes can be modified in ICP mode (via SWIM) by accessing the EEPROM address
shown in Table 12: Option bytes below. Option bytes can also be modified ‘on the fly’ by the
application in IAP mode, except the ROP option that can only be modified in ICP mode (via SWIM).
Refer to the STM8S Flash programming manual (PM0051) and STM8 SWIM
communication protocol and debug module user manual (UM0470) for information on SWIM
programming procedures.