Datasheet

MC68HC908QY4•MC68HC908QT4•MC68HC908QY2•MC68HC908QT2•MC68HC908QY1•MC68HC908QT1
46 FLASH Memory (FLASH) MOTOROLA
FLASH Memory (FLASH)
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4.3 Functional Description
The FLASH memory consists of an array of 4096 or 1536 bytes with an
additional 48 bytes for user vectors. The minimum size of FLASH
memory that can be erased is 64 bytes; and the maximum size of FLASH
memory that can be programmed in a program cycle is 32 bytes (a row).
Program and erase operations are facilitated through control bits in the
FLASH control register (FLCR). Details for these operations appear later
in this section. The address ranges for the user memory and vectors are:
• $EE00 – $FDFF; user memory, 4096 bytes: MC68HC908QY4 and
MC68HC908QT4
• $F800 – $FDFF; user memory, 1536 bytes: MC68HC908QY2,
MC68HC908QT2, MC68HC908QY1 and MC68HC908QT1
• $FFD0 – $FFFF; user interrupt vectors, 48 bytes.
NOTE: An erased bit reads as logic 1 and a programmed bit reads as logic 0.
A security feature prevents viewing of the FLASH contents.
(1)
1. No security feature is absolutely secure. However, Motorola’s strategy is to make reading or
copying the FLASH difficult for unauthorized users.