Rev. 1.0
83
Si4010-C2
24.12. Boot and Retest Protection NVM Control Byte
The boot process monitors the value of an NVM byte called
PROT3_CTRL
. There is not a corresponding
hardware register to this byte. It is a value in the
Factory
region at the beginning of NVM. The register
contains
Retest
protection flags described above and modification of the boot for
User
part.
Each bit is write 1 once. Once the bit is programmed it cannot be cleared. The bits are programmable
though the checkboxes in the NVM programmer. Once the bit is set, there is no way to monitor the current
status of the bit in the PROT3_CTRL NVM byte on the device.
NVM Byte Definition 24.3. PROT3_CTRL
Bit
7
6
5
4
3
2
1
0
Name
NVM_C2_
PROT
MTP_C2_
PROT
MEM_C2_
PROT
BOOT_XO
_ENA
Reserved
USER_
CONT
Reserved
Type
W
W
W
W
R
W
R
Reset
0
0
0
0
0x0
0
0
Bit
Name
Function
7
NVM_C2_
PROT
NVM Protection (Disable) When Entering Retest Mode.
This bit corresponds to
NVM Disable
checkbox on the NVM programmer GUI.
6
MTP_C2_PR
OT
MTP Protection (Disable) When Entering Retest Mode.
This bit corresponds to
MTP Disable
checkbox on the NVM programmer GUI.
5
MEM_C2_
PROT
RAM Clearing (Content Protection) When Entering Retest Mode.
This bit corresponds to
RAM Clear
checkbox on the NVM programmer GUI.
4
BOOT_XO_
ENA
Enable the Crystal Oscillator (XO) at the Beginning of the Boot Process.
This is valid in any device programming level, including
Factory
. Since it can take up to 10ms
for the XO to stabilize and about 3.6 ms to load 1 kB of data from NVM to RAM, the user may
decide to enable the XO at the beginning of the boot process so the XO will be stabilizing
while the device is going through the boot process to save time in the main application.
This bit corresponds to
XO Early Enable
checkbox on the NVM programmer GUI.
2:3
Reserved
Reserved.
1
USER_CONT
Run the User Code in User Part after Boot Automatically.
For
User
programming level only, has no effect in other programming levels. Normally when
the part is programmed as User the user code is loaded from NVM to RAM, but is not
executed automatically. If this bit is set, then the user load is executed automatically after boot.
This bit corresponds to
Exe User Boot
checkbox on the NVM programmer GUI.
0
Reserved
Reserved.