Write/Erase Modes - Fujitsu MB96300 series Hardware Manual

33.3

Write/Erase Modes

The flash memory can be accessed in two different ways: Flash memory mode and
alternative mode. Flash memory mode enables data to be directly written to or erased
from the external pins. Alternative mode enables data to be written to or erased from the
CPU via the internal bus. Use the mode pins MD[2:0] to select the mode as described in
Table 8.4-1.
■ Flash memory mode
The CPU stops when the mode pins are set to MD[2:0] = 111 while the reset signal is asserted. The flash
memory interface circuit is connected directly to ports as described in the datasheet, enabling direct control
from the external pins. This mode makes the MCU seem like a standard flash memory to the external pins,
and write/erase can be performed using a flash memory programmer.
In flash memory mode, all operations supported by the flash memory automatic algorithm can be used.
■ Alternative mode (CPU mode)
The flash memory is located in the DF to FF banks in the CPU memory space. Like ordinary mask ROM, it
can be read-accessed and program-accessed from the CPU via the flash memory interface circuit.
Since writing/erasing the flash memory is performed by instructions from the CPU via the flash memory
interface circuit, this mode allows rewriting even when the MCU is soldered on the target board.
■ Flash memory control signals
There is almost a one-to-one correspondence between the flash memory control signals and the external
pins of the MBM29LV200TC.
For a detailed description of the pin location of the Flash memory control signals please refer to the
datasheet.
Note:
The sector protect function of MBM29LV200TC via V
sector write protection that prevents accidental erase/write in alternative mode. Please refer to 33.4.3
Flash Memory Write Control registers 0-5 (FMWC0-FMWC5) for details.
CHAPTER 33 FLASH MEMORY
(12 V) pin is not supported. Instead, there is a
ID
843