mc9s12xd256 Freescale Semiconductor, Inc, mc9s12xd256 Datasheet - Page 1118

• Manufacturer Part Number: mc9s12xd256
• Description: Hcs12x Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Chapter 27 512 Kbyte Flash Module (S12XFTX512K4V2)
27.3.2.5
The FPROT register defines which Flash sectors are protected against program or erase operations.
All bits in the FPROT register are readable and writable with restrictions (see
Protection
During the reset sequence, the FPROT register is loaded from the Flash Configuration Field at global
address 0x7F_FF0D. To change the Flash protection that will be loaded during the reset sequence, the
upper sector of the Flash memory must be unprotected, then the Flash Protect/Security byte located as
described in
Trying to alter data in any protected area in the Flash memory will result in a protection violation error and
the PVIOL flag will be set in the FSTAT register. The mass erase of a Flash block is not possible if any of
the Flash sectors contained in the Flash block are protected.
1118
FPHS[1:0]
FPOPEN
FPHDIS
Reset
RNV6
Field
4–3
7
6
5
W
R
FPOPEN
Restrictions”) except for RNV[6] which is only readable.
Flash Protection Open — The FPOPEN bit determines the protection function for program or erase as shown
in
0 The FPHDIS and FPLDIS bits define unprotected address ranges as specified by the corresponding
1 The FPHDIS and FPLDIS bits enable protection for the address range specified by the corresponding
Reserved Nonvolatile Bit — The RNV[6] bit should remain in the erased state for future enhancements.
Flash Protection Higher Address Range Disable — The FPHDIS bit determines whether there is a
protected/unprotected area in a specific region of the Flash memory ending with global address 0x7F_FFFF.
0 Protection/Unprotection enabled.
1 Protection/Unprotection disabled.
Flash Protection Higher Address Size — The FPHS[1:0] bits determine the size of the protected/unprotected
area as shown
Table 27-1
Flash Protection Register (FPROT)
F
7
Table
FPHS[1:0] and FPLS[1:0] bits. For an MCU without an EEPROM module, the FPOPEN clear state allows the
main part of the Flash block to be protected while a small address range can remain unprotected for EEPROM
emulation.
FPHS[1:0] and FPLS[1:0] bits.
27-12.
= Unimplemented or Reserved
RNV6
must be reprogrammed.
inTable
F
6
Figure 27-10. Flash Protection Register (FPROT)
27-13. The FPHS[1:0] bits can only be written to while the FPHDIS bit is set.
Table 27-10. Flash Register Bank Selects
BKSEL[1:0]
Table 27-11. FPROT Field Descriptions
FPHDIS
MC9S12XDP512 Data Sheet, Rev. 2.17
10
11
F
5
F
4
Description
FPHS
Selected Block
Flash Block 2
Flash Block 3
F
3
FPLDIS
F
2
Section 27.3.2.5.1, “Flash
Freescale Semiconductor
F
1
FPLS
F
0