
25. Flash Memory
25. Flash Memory
CPU rewrite mode, standard serial I/O mode, and parallel I/O mode can be used to program and erase the flash
memory.
Table 25.1 lists specifications of the flash memory. See Tables 1.1 to 1.4 Specifications for the items not listed in
Table 25.1
Flash Memory Specifications
NOTES:
1. The rewrite control program for standard serial I/O mode is stored in the boot ROM area in the factory default
configuration. This area can be rewritten only in parallel I/O mode.
2. The flash memory can be programmed in byte only in parallel I/O mode.
3. The programming and erasure endurance is defined on a per-block basis. For example, if 1-word or more
writes are performed to block A and then the block is erased, the programming and erasure count stands at one
for block A.
Table 25.2
Flash Memory Rewrite Mode Overview
Item
Specification
Flash memory operating mode
3 modes (CPU rewrite mode, standard serial I/O mode, parallel I/O mode)
Erase block
User ROM area
Boot ROM area
Program method
In word (16 bits), in byte (8 bits)
(2)Erase method
Erase per block
Program and erase control method
Software commands control programming and erasing on the flash memory
Protect method
The lock bit protects each block in the flash memory
Number of commands
7 commands
Programming and erasure endurance 100 ti
mes(3)Flash memory access disable function ROM code protection function (parallel I/O mode)
ID code check function (standard serial I/O mode)
Flash Memory
Rewrite Mode
CPU Rewrite Mode
Standard Serial I/O Mode
Parallel I/O Mode
Function
User ROM area is rewritten by
the CPU executing software
commands.
Execute the rewrite control
program placed in an area
outside the flash memory.
User ROM area is rewritten
using a dedicated serial
programmer.
Standard serial I/O mode 1:
Clock synchronous serial I/O
Standard serial I/O mode 2:
Clock asynchronous serial I/O
User ROM and boot ROM
areas are rewritten using a
dedicated parallel
programmer.
Rewritable area
User ROM area
Boot ROM area
Operating mode
Single-chip mode
Boot mode
Parallel I/O mode
ROM programmer
Serial programmer
Parallel programmer