tmp89fh42l TOSHIBA Semiconductor CORPORATION, tmp89fh42l Datasheet - Page 336

• Manufacturer Part Number: tmp89fh42l
• Description: 8 Bit Microcontroller Tlcs-870/c1 Series
• Manufacturer: TOSHIBA Semiconductor CORPORATION

21.2
Functions
RA006
21.2.2
be executed. If a memory transfer instruction is used to read or write data, a read or write can be performed only
on the data area. To perform an erase or write on the code area, therefore, part of the code area must be temporarily
switched to the data area. This switching between data and code areas is performed by making the appropriate
FLSCR1<FAREA> setting.
(AREA C1) in the code area is mapped to 0xC000 through 0xFFFF (AREA D1) in the data area.
on FLSCR2<CR1EN>.
the memory transfer instruction on 0xC000 through 0xFFFF (AREA D1) in the data area.
area are mirror areas; these two areas refer to the same physical address in memory. Therefore, an erase or write
must be performed on one of these two mirror areas. For example, If a write is performed on 0xC000 in the data
area with FLSCR1<FAREA> set to "10" after performing a write on 0xC000 in the data area with
FLSCR1<FAREA> set to "00", data is overwritten. To write data to the flash memory that already has data written
to it, existing data must first be erased from the flash memory by performing a sector erase or chip erase, and then
data must be written.
or specifying such an area by using jump or call instructions.
To perform an erase or write on the flash memory, a memory transfer instruction (command sequence) must
By setting "0xD5" on FLSCR2<CR1EN> after setting FLSCR1<FAREA> to "10", 0xC000 through 0xFFFF
To restore the flash memory to the initial state of mapping, set FLSCR1<FAREA> to "00", and then set "0xD5"
All flash memory areas can be accessed by performing the appropriate steps described above and then executing
0xC000 through 0xFFFF (AREA D1) in the data area and 0xC000 through 0xFFFF (AREA C1) in the code
Additionally, access to areas to which memory is not assigned should be avoided by executing an instruction
Flash memory area switching (FLSCR1<FAREA>)
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