Data Sheet — MC68HC908MR32 • MC68HC908MR16
Section 2. Memory
2.1 Introduction
The central processor unit (CPU08) can address 64 Kbytes of memory space. The
memory map, shown in Figure 2-1, includes:
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32 Kbytes of FLASH
768 bytes of random-access memory (RAM)
46 bytes of user-defined vectors
240 bytes of monitor read-only memory (ROM)
2.2 Unimplemented Memory Locations
Some addresses are unimplemented. Accessing an unimplemented address can
cause an illegal address reset. In the memory map and in the input/output (I/O)
register summary, unimplemented addresses are shaded.
Some I/O bits are read only; the write function is unimplemented. Writing to a
read-only I/O bit has no effect on microcontroller unit (MCU) operation. In register
figures, the write function of read-only bits is shaded.
Similarly, some I/O bits are write only; the read function is unimplemented. Reading
of write-only I/O bits has no effect on MCU operation. In register figures, the read
function of write-only bits is shaded.
2.3 Reserved Memory Locations
Some addresses are reserved. Writing to a reserved address can have
unpredictable effects on MCU operation. In the memory map (Figure 2-1) and in
the I/O register summary (Figure 2-2) reserved addresses are marked with the
word reserved.
Some I/O bits are reserved. Writing to a reserved bit can have unpredictable effects
on MCU operation. In register figures, reserved bits are marked with the letter R.
MC68HC908MR32 • MC68HC908MR16 — Rev. 6.0
MOTOROLA
Data Sheet
27
Memory
FREESCALE [ Freescale ]
