Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
Freescale Semiconductor
MC9S12C-Family / MC9S12GC-Family
505
Rev 01.24
18.3
Memory Map and Registers
This section describes the
FTS32K
memory map and registers.
18.3.1
Module Memory Map
The
FTS32K
memory map is shown in
. The HCS12 architecture places the Flash array
addresses between
0x4000
and 0xFFFF
, which corresponds to three 16 Kbyte pages
. The content of the
HCS12 Core PPAGE register is used to map the logical
middle
page ranging from 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 18-2.
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 18-1. 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 18.3.2.5, “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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