23.2.2 Operating Mode
When each mode pin and the FWE pin are set in the reset state and the reset signal is released, the
microcomputer enters each operating mode as shown in figure 23.2. For the setting of each mode
pin and the FWE pin, see table 23.1.
• Flash memory cannot be read, programmed, or erased in ROM invalid mode. The
programming/erasing interface registers cannot be written to. When these registers are read,
H'00 is always read.
• Flash memory can be read in user mode, but cannot be programmed or erased.
• Flash memory can be read, programmed, or erased on the board only in user program mode,
user boot mode, and boot mode.
• Flash memory can be read, programmed, or erased by means of the PROM programmer in
programmer mode.
Ну вот как-то так...