R01UH0822EJ0100 Rev.1.00
Page 911 of 1041
Jul 31, 2019
RX13T Group
31. Flash Memory (FLASH)
31.4.2
Flash P/E Mode Entry Register (FENTRYR)
To rewrite the ROM or E2 DataFlash, the FENTRYD or FENTRY0 bit must be set to 1 to place the ROM or E2
DataFlash in P/E mode.
When returning to read mode, set the FENTRYR register and confirm that its value has been rewritten before reading the
ROM or E2 DataFlash.
Refer to
section 31.7.1, Sequencer Modes
for details on P/E mode and read mode.
FENTRY0 Bit (ROM P/E Mode Entry 0)
This bit is used to place the ROM in P/E mode.
[Setting condition]
AA01h is written to the FENTRYR register when the FENTRYR register is 0000h.
Note:
When entering ROM P/E mode, the instruction fetch address must be transferred to an area other than the ROM
so that instruction fetching is not executed to the ROM. Copy necessary instruction code to the internal RAM and
jump to the RAM. Note that E2 DataFlash can be rewritten by a program in the ROM.
[Clearing condition]
AA00h is written to the FENTRYR register.
FENTRYD Bit (E2 DataFlash P/E Mode Entry)
This bit is used to place the E2 DataFlash in P/E mode.
[Setting condition]
AA80h is written to the FENTRYR register when the FENTRYR register is 0000h.
[Clearing condition]
AA00h is written to the FENTRYR register.
Address(es): FLASH.FENTRYR 007F FFB2h
b15
b14
b13
b12
b11
b10
b9
b8
b7
b6
b5
b4
b3
b2
b1
b0
FEKEY[7:0]
FENTR
YD
—
—
—
—
—
—
FENTR
Y0
Value after reset:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Bit
Symbol
Bit Name
Description
R/W
b0
ROM P/E Mode Entry 0
0: ROM is in read mode.
1: ROM can be placed in P/E mode.
R/W
b6 to b1
—
Reserved
These bits are read as 0. The write value should be 0.
R/W
b7
E2 DataFlash P/E Mode
Entry
0: E2 DataFlash is in read mode.
1: E2 DataFlash can be placed in P/E mode.
R/W
b15 to b8
Key Code
The FEKEY[7:0] bits are used to control rewriting of the FENTRYR
register.
When rewriting the value of the lower 8 bits, set the FEKEY[7:0] bits to
AAh at the same time (write this register in 16 bits).
The FEKEY[7:0] bits are read as 00h.
R/W