Datasheet
Option bytes STM8L151x2, STM8L151x3
98/112 Doc ID 018780 Rev 4
Table 56. 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: UBC is not protected.
0x01: Page 0 is write protected.
0x02: Page 0 and 1 reserved for the UBC and write protected. It covers only the interrupt vectors.
0x03: Page 0 to 2 reserved for UBC and write protected.
0x7F to 0xFF - All 128 pages reserved for UBC and write protected.
The protection of the memory area not protected by the UBC is enabled through the MASS keys.
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 28: LSE oscillator characteristics on page 67.