diff --git a/stm-firmware/include/stm-periph/option-bytes.h b/stm-firmware/include/stm-periph/option-bytes.h
new file mode 100644
index 0000000..f375dda
--- /dev/null
+++ b/stm-firmware/include/stm-periph/option-bytes.h
@@ -0,0 +1,45 @@
+/* Reflow Oven Controller
+ *
+ * Copyright (C) 2020  Mario Hüttel <mario.huettel@gmx.net>
+ *
+ * This file is part of the Reflow Oven Controller Project.
+ *
+ * The reflow oven controller is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * GDSII-Converter is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with the reflow oven controller project.
+ * If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _OPTION_BYTES_H_
+#define _OPTION_BYTES_H_
+
+#include <stdint.h>
+
+struct option_bytes {
+	/* Word 1 */
+	uint32_t read_protection;// : 8;
+	uint32_t nrst_standby;// : 1;
+	uint32_t nrst_stop;// : 1;
+	uint32_t wdg_sw;// : 1;
+	uint32_t brown_out_level;// : 2;
+	/* Word 2 */
+	uint32_t nwrpi;// : 12;
+};
+
+/**
+ * @brief Read out the option bytes to structs
+ * @param opts
+ */
+void stm_option_bytes_read(struct option_bytes *opts);
+
+int stm_option_bytes_program(const struct option_bytes *opts);
+
+#endif /* _OPTION_BYTES_H_ */
diff --git a/stm-firmware/stm-periph/option-bytes.c b/stm-firmware/stm-periph/option-bytes.c
new file mode 100644
index 0000000..9668de5
--- /dev/null
+++ b/stm-firmware/stm-periph/option-bytes.c
@@ -0,0 +1,48 @@
+/* Reflow Oven Controller
+ *
+ * Copyright (C) 2021  Mario Hüttel <mario.huettel@gmx.net>
+ *
+ * This file is part of the Reflow Oven Controller Project.
+ *
+ * The reflow oven controller is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * The Reflow Oven Control Firmware is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with the reflow oven controller project.
+ * If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stm-periph/option-bytes.h>
+#include <stm32/stm32f4xx.h>
+
+void stm_option_bytes_read(struct option_bytes *opts)
+{
+	uint32_t opt_reg;
+
+	if (!opts)
+		return;
+
+	opt_reg = FLASH->OPTCR;
+	opts->brown_out_level = (opt_reg & FLASH_OPTCR_BOR_LEV) >> 2;
+	opts->nrst_standby = (opt_reg & FLASH_OPTCR_nRST_STDBY) >> 7;
+	opts->nrst_stop = (opt_reg & FLASH_OPTCR_nRST_STOP) >> 6;
+	opts->nwrpi = (opt_reg & FLASH_OPTCR_nWRP) >> 16;
+	opts->read_protection = (opt_reg & FLASH_OPTCR_RDP) >> 8;
+	opts->wdg_sw = (opt_reg & FLASH_OPTCR_WDG_SW) >> 5;
+}
+
+int stm_option_bytes_program(const struct option_bytes *opts)
+{
+	FLASH->OPTKEYR = 0x08192A3BUL;
+	FLASH->OPTKEYR = 0x4C5D6E7FUL;
+
+
+	FLASH->OPTCR |= FLASH_OPTCR_OPTLOCK;
+	return 0;
+}