Datasheet

Option bytes STM8L151xx, STM8L152xx
58/131 DocID15962 Rev 13
Table 13. Option byte description
Option
byte
No.
Option description
OPT0
ROP[7:0] Memory readout protection (ROP)
0xAA: Disable readout protection (write access via SWIM protocol)
Refer to Readout protection section in the STM8L15x and STM8L16x reference manual (RM0031).
OPT1
UBC[7:0] Size of the user boot code area
0x00: no UBC
0x01: the UBC contains only the interrupt vectors.
0x02: Page 0 and 1 reserved for the UBC and read/write protected. Page 0 contains only the interrupt
vectors.
0x03 - Page 0 to 2 reserved for UBC, memory write-protected
0xFF - Page 0 to 254 reserved for UBC, memory write-protected
Refer to User boot code section in the STM8L15x and STM8L16x reference manual (RM0031).
OPT2 Reserved
OPT3
IWDG_HW: Independent watchdog
0: Independent watchdog activated by software
1: Independent watchdog activated by hardware
IWDG_HALT: Independent window watchdog off on Halt/Active-halt
0: Independent watchdog continues running in Halt/Active-halt mode
1: Independent watchdog stopped in Halt/Active-halt mode
WWDG_HW: Window watchdog
0: Window watchdog activated by software
1: Window watchdog activated by hardware
WWDG_HALT: Window window watchdog reset on Halt/Active-halt
0: Window watchdog stopped in Halt mode
1: Window watchdog generates a reset when MCU enters Halt mode
OPT4
HSECNT: Number of HSE oscillator stabilization clock cycles
0x00 - 1 clock cycle
0x01 - 16 clock cycles
0x10 - 512 clock cycles
0x11 - 4096 clock cycles
LSECNT: Number of LSE oscillator stabilization clock cycles
0x00 - 1 clock cycle
0x01 - 16 clock cycles
0x10 - 512 clock cycles
0x11 - 4096 clock cycles
Refer to Table 32: LSE oscillator characteristics on page 81.