R01UH0823EJ0100 Rev.1.00
Page 1671 of 1823
Jul 31, 2019
RX23W Group
50. Flash Memory (FLASH)
50.4.10
Flash Extra Area Control Register (FEXCR)
Note 1. This does not include set the FEXCR register to 00h when the FSTATR1.EXRDY flag is 1.
Data can be written to the FEXCR register when in ROM P/E mode and the ROM can be programmed/erased.
This register is initialized by a reset or setting the FRESETR.FRESET bit to 1. Data cannot be written to this register
while the FRESETR.FRESET bit is 1.
Note that this register cannot be initialized by the FRESETR.FRESET bit while a software command is being executed.
CMD[2:0] Bits (Software Command Setting)
These bits are used to set a software command (start-up area information program or access window information
program).
The details of each command are described below.
[Start-up area information program]
This command is used to switch the start-up area used for start-up program protection.
When setting the start-up area to the default area
Set registers FWB0, FWB1, FWB2, and FWB3 to FFFFh, and execute this command.
When setting the start-up area to the alternative area
Set the FWB0 register to FEFFh, set registers FWB1, FWB2, and FWB3 to FFFFh, and execute this command.
When registers FWB0, FWB1, FWB2, and FWB3 are set to values other than the above, do not execute the start-up area
information program.
[Access window information program]
This command is used to set the access window used for area protection.
Set the access window in block units.
Specify the access window start address, which is the beginning address of the access window in the FWB0 register,
specify the access window end address, which is the next address of the last address of the access window in the FWB1
register, and issue this command. Set bit 21 to bit 10 of the address for programming/erasure in each register.
If the same value is set as the start address and end address, all areas can be accessed. Do not set the start address to a
value larger than the value of the end address.
This bit is used to execute the command set in the CMD[2:0] bits.
This bit is not set to 0 again even when the processing is completed. Confirm that the FSTATR1.EXRDY flag is 1
(processing completed) before setting the OPST bit to 0 again. After that, confirm that the FSTATR1.EXRDY flag is 0
before executing the next processing.
Address(es): FLASH.FEXCR 007F C1DCh
b7
b6
b5
b4
b3
b2
b1
b0
OPST
—
—
—
—
CMD[2:0]
Value after reset:
0
0
0
0
0
0
0
0
Bit
Symbol
Bit Name
Description
R/W
b2 to b0
Software Command Setting
b2 b0
0 0 1: Start-up area information program
0 1 0: Access window information program
Settings other than above are prohibited.*
R/W
b6 to b3
—
Reserved
These bits are read as 0. The write value should be 0.
R/W
b7
Processing Start
0: Processing stops.
1: Processing starts.
R/W