BLOCK0 data register 4.
| DIS_DOWNLOAD_MODE | Represents whether Download mode is disabled or enabled. 1: disabled. 0: enabled. |
| DIS_DIRECT_BOOT | Represents whether direct boot mode is disabled or enabled. 1: disabled. 0: enabled. |
| DIS_USB_SERIAL_JTAG_ROM_PRINT | Represents whether print from USB-Serial-JTAG is disabled or enabled. 1: disabled. 0: enabled. |
| LOCK_KM_KEY | TBD |
| DIS_USB_SERIAL_JTAG_DOWNLOAD_MODE | Represents whether the USB-Serial-JTAG download function is disabled or enabled. 1: disabled. 0: enabled. |
| ENABLE_SECURITY_DOWNLOAD | Represents whether security download is enabled or disabled. 1: enabled. 0: disabled. |
| UART_PRINT_CONTROL | Represents the type of UART printing. 00: force enable printing. 01: enable printing when GPIO8 is reset at low level. 10: enable printing when GPIO8 is reset at high level. 11: force disable printing. |
| FORCE_SEND_RESUME | Represents whether ROM code is forced to send a resume command during SPI boot. 1: forced. 0:not forced. |
| SECURE_VERSION | Represents the version used by ESP-IDF anti-rollback feature. |
| SECURE_BOOT_DISABLE_FAST_WAKE | Represents whether FAST VERIFY ON WAKE is disabled or enabled when Secure Boot is enabled. 1: disabled. 0: enabled. |
| HYS_EN_PAD | Represents whether the hysteresis function of corresponding PAD is enabled. 1: enabled. 0:disabled. |
| DCDC_VSET | Set the dcdc voltage default. |