ST10F272B_12 STMICROELECTRONICS [STMicroelectronics], ST10F272B_12 Datasheet - Page 41

• Manufacturer Part Number: ST10F272B_12
• Description: 16-bit MCU with 256 Kbyte Flash memory and 12/20 Kbyte RAM
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

ST10F272B/ST10F272E
5.5.5
5.5.6
5.5.7
Flash non volatile access protection register 1 high
FNVAPR1H (0x08 DFBE)
PEN15PEN14PEN13PEN12PEN11PEN10 PEN9 PEN8 PEN7 PEN6 PEN5 PEN4 PEN3 PEN2 PEN1 PEN0
Table 22.
XBus flash volatile temporary access unprotection register (XFVTAUR0)
XFVTAUR0 (0x00 EB50)
Table 23.
Access protection
The I-Flash module has one level of access protection (access to data both in Reading and
Writing): if bit ACCP of FNVAPR0 is programmed at 0 and bit TAUB in XFVTAUR0 is set at
0, the I-Flash module becomes access protected: data in the I-Flash module can be read
only if the current execution is from the I-Flash module itself.
To enable Access Protection, the following sequence of operations is recommended:
●
●
●
●
●
Protection can be permanently disabled by programming bit PDS0 of FNVAPR1H, in order
to analyze rejects. Protection can be permanently enabled again by programming bit PEN0
of FNVAPR1L. The action to disable and enable again Access Protections in a permanent
PEN15-0
TAUB
RW
15
15
execution from external memory or internal Rams
program TAUB bit at 1 in XFVTAUR0 register
program ACCP bit in FNVAPR0 to 0 using Set Protection operation
program TAUB bit at 0 in XFVTAUR0 register
Access Protection is active when both ACCP bit and TAUB bit are set to 0.
Bit
Bit
RW
14
14
RW
Flash non volatile access protection register 1 high
XBus flash volatile temporary access unprotection register
13
13
Protections Enable 15-0
If bit PENx is programmed at 0 and bit PDSx+1 is erased at 1, the action of bit
ACCP is enabled again. Bit PENx can be programmed at 0 only if bit PDSx has
already been programmed at 0.
Temporary Access Unprotection bit
If this bit is set to 1, the Access Protection is temporary disabled.
This bit can be written only executing from IFlash.This fact guarantees that only a
code executed in IFlash, can unprotect the IFlash, when it is Access Protected.
RW
12
12
RW
11
11
RW
Doc ID 11917 Rev 3
10
10
RW
9
9
reserved
NVR
NVR
RW
8
8
RW
7
7
Function
Function
RW
6
6
RW
5
5
RW
4
4
Internal Flash memory
RW
3
3
Delivery value: FFFFh
Reset value: 0000h
RW
2
2
RW
1
1
41/188
TAUB
RW
RW
0
0