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6. ROM
6.2.3
Flash Memory Operating Modes
Mode Transition Diagram: When the TEST
a reset start is effected, the chip enters one of the operating modes shown in figure 6.3. In user
mode, the flash memory can be read but cannot be programmed or erased.
Modes in which the flash memory can be programmed and erased are boot mode, user program
mode, and Writer mode.
User mode
TEST2 = 1,
FWE = 1,
SWE = 1
Notes:
Transitions between user mode and user program mode should only be
made when the CPU is not accessing the flash memory.
*
TEST2 = 0, TEST = 1
PB6 = PB5 = 1
PB4 = 0
Rev.3.00 Jul. 19, 2007 page 122 of 532
REJ09B0397-0300
FWE = 0
or
SWE = 0
User
program
mode
On-board programming mode
Figure 6.3 Flash Memory Related State Transitions
, TEST, and FWE pins are set in the reset state and
2
Reset state
Boot mode
RES = 0
*
Writer mode
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