CHAPTER 17 FLASH MEMORY
Outline of Flash Memory
The MB91F355A, MB91F353A and MB91F357B each contain two 256K bytes flash
memories for a combined total flash memory capacity of 512K bytes.
The MB91F356B contains two 128K bytes Flash memories for combined total flash
memory capacity of 256K bytes.
The internal flash memory operates on a single power supply voltage of 3.3 V. The
internal flash memory can be erased by sector, batch-erased (all sectors erased), and
written in halfword (16 bits) units via the FR-CPU.
■ Outline of Flash Memory
The flash memory employed is an internal 256K bytes/128K bytes flash memory that operates on 3.3 V.
The flash memory employed here is the same (except for the capacity and sector structure) as the Fujitsu
MBM29LV400C flash memory. The flash memory supports writing with a device-external ROM writer.
Along with this manual, refer to the MBM29LV400C Data Sheet.
In addition to the features equivalent to the MBM29LV400C, instructions and data can be read in word
units (32 bits) when the flash memory is used as FR-CPU internal ROM, enabling high-speed device
operation. The MB91F355A, MB91F353A, MB91F356B and MB91F357B each contain two flash
The MB91F355A, MB91F353A, MB91F356B and MB91F357B support the following features by
combining the internal flash memories and the FR-CPU interface circuits:
Features for use as CPU memory, for storing programs and data (referred to hereafter as CPU mode.)
- Accessibility through 32-bit bus when used as ROM
- Allowing read, write, and erase (automatic program algorithm
Features of a single flash memory product equivalent to MBM29LV400 (referred to hereafter as
- Allowing read, write, or erase (automatic program algorithm
This section explains use of the flash memory accessed from the FR-CPU.
For information on using the flash memory accessed from a ROM writer, see the instruction manual
provided with the ROM writer.
*: Automatic program algorithm: embedded Algorithm
Note: Embedded Algorithm
is a trademark of Advanced Micro Devices, Inc.
) by the CPU instruction
) by a ROM writer