Datasheet

V850ES/JG3-H, V850ES/JH3-H CHAPTER 31 FLASH MEMORY
R01UH0042EJ0500 Rev.5.00 Page 1383 of 1513
Aug 12, 2011
31.5.2 Features
(1) Secure self programming (boot swap function)
The V850ES/JG3-H and V850ES/JH3-H support a boot swap function that can exchange the physical memory of
blocks 0 to 15 with the physical memory of blocks 16 to 31. By writing the start program to be rewritten to blocks
16 to 31 in advance and then swapping the physical memory, the entire area can be safely rewritten even if a
power failure occurs during rewriting because the correct user program always exists in blocks 0 to 15.
Figure 31-17. Rewriting Entire Memory Area (Boot Swap)
Block 0
Block 1
:
Block 15
Block 16
Block 17
:
Block 31
Block 32
:
Last block
Block 0
Block 1
:
Block 15
Block 16
Block 17
:
Block 31
Block 32
:
Last block
Block 0
Block 1
:
Block 15
Block 16
Block 17
:
Block 31
Block 32
:
Last block
Boot swap
Rewriting blocks
16 to 31
(2) Interrupt support
Instructions cannot be fetched from the flash memory during self-programming. Consequently, a user handler
written to the flash memory could not be used even if an interrupt has occurred.
Therefore, in the V850ES/JG3-H and V850ES/JH3-H, to use an interrupt during self-programming, processing
transits to the specific address
Note
in the internal RAM. Allocate the jump instruction that transits processing to the
user interrupt servicing at the specific address
Note
in the internal RAM.
Note NMI interrupt: Start address of internal RAM
Maskable interrupt: Start address of internal RAM + 4 addresses