HD64F2357VF13 Datasheet, PDF (667/1049 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Do not change the mode pin input levels in boot mode.
• If the mode pin input levels are changed (for example, from low to high) during a reset, the state of ports with
multiplexed address functions and bus control output pins (AS, RD, HWR) will change according to the change in the
microcomputer’s operating mode*².
Therefore, care must be taken to make pin settings to prevent these pins from becoming output signal pins during a
reset, or to prevent collision with signals outside the microcomputer.
Notes: 1. Mode pins input must satisfy the mode programming setup time (t_MDS = 200 ns) with respect to the reset release
timing.
2. See Appendix D, Pin States.
19.17.2 User Program Mode
When set to user program mode, the chip can program and erase its flash memory by executing a user program/erase
control program. Therefore, on-board reprogramming of the on-chip flash memory can be carried out by providing on-
board means supply of programming data, and storing a program/erase control program in part of the program area if
necessary.
To select user program mode, select a mode that enables the on-chip flash memory (mode 6 or 7). In this mode, on-chip
supporting modules other than flash memory operate as they normally would in modes 6 and 7.
The flash memory itself cannot be read while the SWE bit is set to 1 to perform programming or erasing, so the control
program that performs programming and erasing should be run in on-chip RAM or external memory. When the program is
located in external memory, an instruction for programming the flash memory and the following instruction should be
located in on-chip RAM.
Figure 19-47 shows the procedure for executing the program/erase control program when transferred to on-chip RAM.
Write the transfer program
(and the program/erase control
program if necessary) beforehand
MD2, MD1, MD0 = 110, 111
Reset-start
Transfer program/erase control
program to RAM
Branch to program/erase control
program in RAM area
Execute program/erase control
program (flash memory rewriting)
Branch to flash memory application
program
Note: The watchdog timer should be activated to prevent overprogramming or overerasing
due to program runaway, etc.
Figure 19-47 User Program Mode Execution Procedure
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