Chapter 24 128 KByte Flash Module (S12XFTM128K2V1)
MC9S12XE-Family Reference Manual , Rev. 1.21
850
Freescale Semiconductor
The (unreserved) bits of the FPROT register are writable with the restriction that the size of the protected
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 0x7F_FF0C located in P-Flash memory (see
Table 24-3)
as indicated by reset condition ‘F’ in
Figure 24-13. 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.
Offset Module Base + 0x0008
76543210
R
FPOPEN
RNV6
FPHDIS
FPHS[1:0]
FPLDIS
FPLS[1:0]
W
Reset
F
FFFFFF
= Unimplemented or Reserved
Figure 24-13. Flash Protection Register (FPROT)
Table 24-19. 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 24-20 for the P-Flash block.
0 When FPOPEN is clear, the FPHDIS and FPLDIS bits dene unprotected address ranges as specied by the
corresponding FPHS and FPLS bits
1 When FPOPEN is set, the FPHDIS and FPLDIS bits enable protection for the address range specied by the
corresponding FPHS and FPLS bits
6
RNV[6]
Reserved Nonvolatile Bit — The RNV bit should remain in the erased state for future enhancements.
5
FPHDIS
Flash Protection Higher Address Range Disable — The FPHDIS bit determines whether there is a
protected/unprotected area in a specic region of the P-Flash memory ending with global address 0x7F_FFFF.
0 Protection/Unprotection enabled
1 Protection/Unprotection disabled
4–3
FPHS[1:0]
Flash Protection Higher Address Size — The FPHS bits determine the size of the protected/unprotected area
in P-Flash memory as shown
inTable 24-21. The FPHS 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 a specic region of the P-Flash memory beginning with global address
0x7F_8000.
0 Protection/Unprotection enabled
1 Protection/Unprotection disabled
1–0
FPLS[1:0]
Flash Protection Lower Address Size — The FPLS bits determine the size of the protected/unprotected area
in P-Flash memory as shown in
Table 24-22. The FPLS bits can only be written to while the FPLDIS bit is set.