MC9S12HZ256 Datasheet, PDF (68/692 Pages) Freescale Semiconductor, Inc – HCS12 Microcontrollers

Chapter 2 256 Kbyte Flash Module (FTS256K2V1)
Table 2-9. FCNFG Field Descriptions
Field
7
CBEIE
6
CCIE
5
KEYACC
0
BKSEL
Description
Command Buffer Empty Interrupt Enable — The CBEIE bit enables an interrupt in case of an empty command
buffer in the Flash module.
0 Command buffer empty interrupt disabled.
1 An interrupt will be requested whenever the CBEIF flag (see Section 2.3.2.7, “Flash Status Register (FSTAT)”)
is set.
Command Complete Interrupt Enable — The CCIE bit enables an interrupt in case all commands have been
completed in the Flash module.
0 Command complete interrupt disabled.
1 An interrupt will be requested whenever the CCIF flag (see Section 2.3.2.7, “Flash Status Register (FSTAT)”)
is set.
Enable Security Key Writing
0 Flash writes are interpreted as the start of a command write sequence.
1 Writes to Flash array are interpreted as keys to open the backdoor. Reads of the Flash array return invalid
data.
Block Select — The BKSEL bit indicates which register bank is active.
0 Select register bank associated with Flash block 0.
1 Select register bank associated with Flash block 1.
2.3.2.5 Flash Protection Register (FPROT)
The banked FPROT register defines which Flash sectors are protected against program or erase operations.
7
6
5
4
3
2
R
FPOPEN
W
RNV6
FPHDIS
FPHS
FPLDIS
Reset
F
F
F
F
F
F
= Unimplemented or Reserved
Figure 2-8. Flash Protection Register (FPROT)
1
0
FPLS
F
F
All bits in the FPROT register are readable and writable with restrictions except for RNV[6] which is only
readable (see Section 2.3.2.6, “Flash Protection Restrictions”).
During reset, the banked FPROT registers are loaded from the Flash Configuration Field at the address
shown in Table 2-10. 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 Table 2-1 must be reprogrammed.
Table 2-10. Reset Loading of FPROT
Flash Address
0xFF0D
0xFF0C
Protection Byte for
Flash Block 0
Flash Block 1
MC9S12HZ256 Data Sheet, Rev. 2.04
68
Freescale Semiconductor