User Manual

Apollo3 Blue Datasheet
DS-A3-0p9p1 Page 137 of 909 2019 Ambiq Micro, Inc.
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3.8.2.18 BOOTLOADER Register
Bootloader and secure boot functions
OFFSET: 0x000001A0
INSTANCE 0 ADDRESS: 0x400201A0
Bootloader and secure boot functions
Table 165: BOOTLOADER Register
3
1
3
0
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
1
9
1
8
1
7
1
6
1
5
1
4
1
3
1
2
1
1
1
0
0
9
0
8
0
7
0
6
0
5
0
4
0
3
0
2
0
1
0
0
SECBOOTONRST
SECBOOT
SECBOOTFEATURE
RSVD
PROTLOCK
SBLOCK
BOOTLOADERLOW
Table 166: BOOTLOADER Register Bits
Bit Name Reset RW Description
31:30
SEC-
BOOTONRST
0x0 RO
Indicates whether the secure boot on warm reset is enabled
DISABLED = 0x0 - Secure boot disabled
ENABLED = 0x1 - Secure boot enabled
ERROR = 0x2 - Error in secure boot configuration
29:28 SECBOOT 0x0 RO
Indicates whether the secure boot on cold reset is enabled
DISABLED = 0x0 - Secure boot disabled
ENABLED = 0x1 - Secure boot enabled
ERROR = 0x2 - Error in secure boot configuration
27:26
SECBOOTFEA-
TURE
0x0 RO
Indicates whether the secure boot feature is enabled.
DISABLED = 0x0 - Secure boot disabled
ENABLED = 0x1 - Secure boot enabled
ERROR = 0x2 - Error in secure boot configuration
25:3 RSVD 0x0 RO
RESERVED.
2PROTLOCK 0x1RW
Flash protection lock. Always resets to 1, write 1 to clear. Enables writes to
flash protection register set.
LOCK = 0x1 - Enable the secure boot lock
1 SBLOCK 0x1 RW
Secure boot lock. Always resets to 1, write 1 to clear. Enables system visi-
bility to bootloader until set.
LOCK = 0x1 - Enable the secure boot lock