MC9S12GRMV1 Datasheet, PDF (1102/1292 Pages) Freescale Semiconductor, Inc – MC9S12G Family Reference Manual and Data Sheet

192 KByte Flash Module (S12FTMRG192K2V1)
30.3.2.9 P-Flash Protection Register (FPROT)
The FPROT register defines which P-Flash sectors are protected against program and erase operations.
Offset Module Base + 0x0008
R
W
Reset
7
FPOPEN
F¹
6
RNV6
F¹
5
FPHDIS
F¹
4
3
FPHS[1:0]
F¹
F¹
2
FPLDIS
F¹
= Unimplemented or Reserved
Figure 30-13. Flash Protection Register (FPROT)
1 _{Loaded from IFR Flash configuration field, during reset sequence.}
1
0
FPLS[1:0]
F¹
F¹
The (unreserved) bits of the FPROT register are writable with the restriction that the size of the protected
region can only be increased (see Section 30.3.2.9.1, “P-Flash Protection Restrictions,” and Table 30-21).
During the reset sequence, the FPROT register is loaded with the contents of the P-Flash protection byte
in the Flash configuration field at global address 0x3_FF0C located in P-Flash memory (see Table 30-4)
as indicated by reset condition ‘F’ in Figure 30-13. To change the P-Flash protection that will be loaded
during the reset sequence, the upper sector of the P-Flash memory must be unprotected, then the P-Flash
protection byte must be reprogrammed. If a double bit fault is detected while reading the P-Flash phrase
containing the P-Flash protection byte during the reset sequence, the FPOPEN bit will be cleared and
remaining bits in the FPROT register will be set to leave the P-Flash memory fully protected.
Trying to alter data in any protected area in the P-Flash memory will result in a protection violation error
and the FPVIOL bit will be set in the FSTAT register. The block erase of a P-Flash block is not possible if
any of the P-Flash sectors contained in the same P-Flash block are protected.
Table 30-17. FPROT Field Descriptions
Field
Description
7
FPOPEN
Flash Protection Operation Enable — The FPOPEN bit determines the protection function for program or
erase operations as shown in Table 30-18 for the P-Flash block.
0 When FPOPEN is clear, the FPHDIS and FPLDIS bits define unprotected address ranges as specified by the
corresponding FPHS and FPLS bits
1 When FPOPEN is set, the FPHDIS and FPLDIS bits enable protection for the address range specified by the
corresponding FPHS and FPLS bits
6
Reserved Nonvolatile Bit — The RNV bit should remain in the erased state 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 a specific region of the P-Flash memory ending with global address 0x3_FFFF.
0 Protection/Unprotection enabled
1 Protection/Unprotection disabled
4–3
Flash Protection Higher Address Size — The FPHS bits determine the size of the protected/unprotected area
FPHS[1:0] in P-Flash memory as shown inTable 30-19. The FPHS bits can only be written to while the FPHDIS bit is set.
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MC9S12G Family Reference Manual, Rev.1.23
Freescale Semiconductor