Rev. 1.0, 02/00, page 126 of 1141
7.2.3
Flash Memory Operating Modes
Mode Transitions
When each mode pin and the FWE pin are set in the reset state and a reset-start is executed, the
MCU enters one of the operating modes shown in figure 7.3. In user mode, flash memory can be
read but not programmed or erased.
Flash memory can be programmed and erased in boot mode, user program mode, and writer mode.
Boot mode
On-board program mode
User
program
mode
User mode
Reset state
Writer mode
FWE = 1, MD0 = 0,
P12 = P13 = P14 = 1
MD0 = 0,
P12 = P13 = 1, P14 = 0
= 0
= 0
FWE = 1
SWE = 1
FWE = 0
or
SWE = 0
= 0
MD1 = 1, FWE = 0 or 1
= 0
Only make a transition between user mode
and user program mode when the CPU is not
accessing the flash memory.
Note:
Figure 7.3 Flash Memory Mode Transitions