### ACS_BOOT_CFG

Bit Field | Read/Write | Field Name | Description
--- | --- | --- | ---
8 | RW | PADS_RETENTION_EN | Enable / Disable the retention mode of the pads
6 | RW | BOOT_ROT_BYPASS | Boot bypass execution of root of trust
5 | RW | BOOT_PWR_CAL_BYPASS | Boot bypass execution of system calibration
4:3 | R | RC_CLOCK_FSEL | RC oscillator clock multiplier read only flag (mirror of CLOCK_MULT of ACS_RCOSC_CTRL register)
2 | R | RC_FTRIM_FLAG | RC oscillator trimming read only flag (mirror of FTRIM_FLAG of ACS_RCOSC_CTRL register
1:0 | RW | BOOT_SELECT | Boot selection to indicate boot source

Bit Field | Field Name | Value Symbol | Value Description | Hex Value
--- | --- | --- | --- | ---
8 | PADS_RETENTION_EN | PADS_RETENTION_DISABLE | Disable the pad retention mode | 0x0*
|  | PADS_RETENTION_ENABLE | Enable the pad retention mode | 0x1
6 | BOOT_ROT_BYPASS | BOOT_ROT_BYPASS_DISABLE | ROM will execute RoT | 0x0*
|  | BOOT_ROT_BYPASS_ENABLE | ROM will not execute RoT | 0x1
5 | BOOT_PWR_CAL_BYPASS | BOOT_PWR_CAL_BYPASS_DISABLE | ROM will execute calibration of system | 0x0*
|  | BOOT_PWR_CAL_BYPASS_ENABLE | ROM will not execute calibration of system | 0x1
4:3 | RC_CLOCK_FSEL | RC_OSC_STATUS_3MHZ | The RC Oscillator is at 3 MHz | 0x0*
|  | RC_OSC_STATUS_12MHZ | The RC Oscillator is at 12 MHz | 0x1
|  | RC_OSC_STATUS_24MHZ | The RC Oscillator is at 24 MHz | 0x2
|  | RC_OSC_STATUS_48MHZ | The RC Oscillator is at 48 MHz | 0x3
2 | RC_FTRIM_FLAG | RC_OSC_STATUS_UNCALIBRATED | The oscillators are not calibrated | 0x0*
|  | RC_OSC_STATUS_CALIBRATED | The oscillators are calibrated | 0x1
1:0 | BOOT_SELECT | BOOT_FLASH_XTAL_DISABLE | The CM33 executes code from the flash and the XTAL will not be started at boot | 0x0*
|  | BOOT_CUSTOM | The CM33 executes code from the address specified in the wakeup information in retention RAM and the XTAL will not be started at boot | 0x1
|  | BOOT_FLASH_XTAL_DEFAULT_TRIM | The CM33 executes code from the flash and the XTAL will be started at boot with the default trim | 0x2
|  | BOOT_FLASH_XTAL_CUSTOM_TRIM | The CM33 executes code from the flash and the XTAL will be started at boot with trim from ACS_WAKEUP_GP_DATA | 0x3