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MCF51QE128 MCU Series Reference Manual, Rev. 3
Freescale Semiconductor 59
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Chapter 4 Memory
NOTE
Peripheral register locations for MCF51QE128/64/32 are shifted
0x(FF)FF_8000 compared with the MC9S08QE128/64/32 devices.
• The ColdFire interrupt controller module is mapped in the peripheral space and occupies a 64-byte
space at the upper end of memory. Accordingly, its address decode is defined as
0x(FF)FF_FFC0–0x(FF)FF_FFFF. This 64-byte space includes the program-visible registers as
well as the space used for interrupt acknowledge (IACK) cycles.
• There is a nonvolatile register area consisting of a 16-byte block locted in flash memory at
0x(00)00_0400–0x(00)00_040F. Nonvolatile register locations include:
— NVPROT and NVOPT are loaded into working registers at reset
— An 8-byte backdoor comparison key that optionally allows a user to gain controlled access to
secure memory
Because the nonvolatile register locations are flash memory, they must be erased and programmed
like other flash memory locations.
Table 4-2 is a summary of all user-accessible direct-page registers and control bits.
The register names in column two in Table 4-2, Table 4-3, Table 4-6, and Table 4-7 are shown in bold to
set them apart from the bit names to the right. Cells not associated with named bits are shaded. A shaded
cell with a 0 indicates this unused bit always reads as a 0. Shaded cells with dashes indicate unused or
reserved bit locations that could read as 1s or 0s. When writing to these bits, write a 0 unless otherwise
specified.
Recall that ColdFire uses a big-endian, byte-addressable memory architecture. The most significant byte
of each address is the lowest numbered as shown in Figure 4-2. Multi-byte operands (16-bit words and
32-bit longwords) are referenced using an address pointing to the most significant (first) byte.
Figure 4-2. ColdFire Memory Organization
Byte 0x(00)00_0000 Byte 0x(00)00_0001 Byte 0x(00)00_0002 Byte 0x(00)00_0003
Word 0x(00)00_0000 Word 0x(00)00_0002
Longword 0x(00)00_0000
31 24 23 16 15 8 7 0
Byte 0x(00)00_0004 Byte 0x(00)00_0005 Byte 0x(00)00_0006 Byte 0x(00)00_0007
Word 0x(00)00_0004 Word 0x(00)00_0006
Longword 0x(00)00_0004
Byte 0x(FF)FF_FFFC Byte 0x(FF)FF_FFFD Byte 0x(FF)FF_FFFE Byte 0x(FF)FF_FFFF
Word 0x(FF)FF_FFFC Word 0x(FF)FF_FFFE
Longword 0x(FF)FF_FFFC
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