Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
540
MC9S12C-Family / MC9S12GC-Family
Freescale Semiconductor
Rev 01.24
address 0x8000 to 0xBFFF to a
ny
physical 16K byte page in the Flash array memory.
1
The FPROT register
(see
) can be set to globally protect the entire Flash array
. Three separate areas, one starting
from the Flash array starting address (called lower) towards higher addresses,
one growing downward from
the Flash array end address
(called higher), and the remaining addresses, can be activated for protection
.
The Flash array addresses covered by these protectable regions are shown in Figure 19-3Figure 19-4.
The
higher address area is mainly targeted to hold the boot loader code since it covers the vector space.
The
lower address area can be used for EEPROM emulation in an MCU without an EEPROM module since it
can be left unprotected while the remaining addresses are protected from program or erase.
Default
protection settings as well as security information that allows the MCU to restrict access to the Flash
module are stored in the Flash configuration field described in
1. By placing
0x3E/
0x3F in the HCS12 Core PPAGE register, the
bottom/top fixed
16 Kbyte page
s
can be seen twice in the MCU
memory map.
Table 19-1. Flash Configuration Field
Flash Address
Size
(bytes)
Description
0xFF00–0xFF07
8
Backdoor Key to unlock security
0xFF08–0xFF0C
5
Reserved
0xFF0D
1
Flash Protection byte
Refer to
Section 19.3.2.5, “Flash Protection Register (FPROT)”
0xFF0E
1
Reserved
0xFF0F
1
Flash Security/Options byte
Refer to
Summary of Contents for MC9S12C Family
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