Start-Up Program Protection - Renesas RX100 Series User Manual

RX13T Group
31.5

Start-Up Program Protection

When rewriting the start-up program *
blackout, the start-up program may not be successfully programmed and the user program may not start properly.
This problem can be avoided by rewriting the start-up program without erasing the existing start-up program using the
start-up program protection. This function is available in products with a 32-Kbyte or larger ROM.
Figure 31.3 shows the Overview of the Start-Up Program Protection. In this figure, the default area indicates block 0 to
block 15, and the alternate area indicates block 16 to block 31.
Note 1. Program to perform operation to start the user program. It includes the fixed vector table.
Address
FFFE 0000h
FFFF 8000h
FFFF C000h
FFFF FFFFh
(1) Program a new start-up program in the alternate area. If the alternate area fails to be rewritten, the new start-up
program can be rewritten again after starting up using the default area, because the original start-up program is
in the default area.
(2) After the alternate area is successfully rewritten, the default area and the alternate area are switched using the
start-up area information program command. After that, the program in the alternate area starts after a reset.
Figure 31.3 Overview of the Start-Up Program Protection
R01UH0822EJ0100 Rev.1.00
Jul 31, 2019
1
by self-programming, if the rewrite operation is interrupted due to temporary
Before rewriting
User program
No program
(alternate area)
Original start-up
program
(default area)
(1)
User program
New start-up
program
(alternate area)
Original start-up
program
(default area)
31. Flash Memory (FLASH)
(2)
User program
Original start-up
program
(default area)
New start-up
program
(alternate area)
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