MC9S12HZ256 Datasheet, PDF (69/692 Pages) Freescale Semiconductor, Inc – HCS12 Microcontrollers

Chapter 2 256 Kbyte Flash Module (FTS256K2V1)
Trying to alter data in any of the protected areas in the Flash block will result in a protection violation error
and the PVIOL flag will be set in the FSTAT register. A mass erase of the Flash block is not possible if
any of the contained Flash sectors are protected.
Table 2-11. FPROT Field Descriptions
Field
Description
7
FPOPEN
Protection Function Bit — The FPOPEN bit determines the protection function for program or erase as shown
in Table 2-12.
0 FPHDIS and FPLDIS bits define unprotected address ranges as specified by the corresponding 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.
1 FPHDIS and FPLDIS bits enable protection for the address range specified by the corresponding FPHS[1:0]
and FPLS[1:0] bits.
6
Reserved Nonvolatile Bit — The RNV[6] bit must remain in the erased state 1 for future enhancements.
RNV[6]
5
FPHDIS
Flash Protection Higher Address Range Disable — The FPHDIS bit determines whether there is a
protected/unprotected area in the higher address space of the Flash block.
0 Protection/Unprotection enabled
1 Protection/Unprotection disabled
4:3
Flash Protection Higher Address Size — The FPHS[1:0] bits determine the size of the protected/unprotected
FPHS[1:0] area as shown in Table 2-13. The FPHS[1:0] bits can only be written to while the FPHDIS bit is set.
2
FPLDIS
Flash Protection Lower address range Disable — The FPLDIS bit determines whether there is a
protected/unprotected area in the lower address space of the Flash block.
0 Protection/Unprotection enabled
1 Protection/Unprotection disabled
1:0
Flash Protection Lower Address Size — The FPLS[1:0] bits determine the size of the protected/unprotected
FPLS[1:0] area as shown in Table 2-14. The FPLS[1:0] bits can only be written to while the FPLDIS bit is set.
Table 2-12. Flash Protection Function
FPOPEN
FPHDIS FPLDIS
Function¹
1
1
1
No Protection
1
1
0
Protected Low Range
1
0
1
Protected High Range
1
0
0
Protected High and Low Ranges
0
1
1
Full Block Protected
0
1
0
Unprotected Low Range
0
0
1
Unprotected High Range
0
0
0
Unprotected High and Low Ranges
1 _{For range sizes, refer to Table 2-13 and Table 2-14.}
MC9S12HZ256 Data Sheet, Rev. 2.04
Freescale Semiconductor
69