M-V850E-IA4 Renesas Electronics America, M-V850E-IA4 Datasheet - Page 762

• Manufacturer Part Number: M-V850E-IA4
• Description: KIT EVAL V850E IA4 UPD70F3186
• Manufacturer: Renesas Electronics America

Specifications of M-V850E-IA4

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

22.5.2 Features
760
(1) Secure self programming (boot swap function)
(2) Interrupt support
The V850E/IA3 and V850E/IA4 support a boot swap function that can exchange the physical memory of blocks
0 and 1 with the physical memory of blocks 2 and 3. By writing the start program to be rewritten to blocks 2
and 3 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 and 1.
Instructions cannot be fetched from the flash memory during self programming. Conventionally, therefore, a
user handler written to the flash memory could not be used even if an interrupt occurred. With the V850E/IA3
and V850E/IA4, a user handler can be registered to an entry RAM area by using a library function, so that
interrupt servicing can be performed by internal RAM or external memory execution.
Block
Block
Block
Block
3
2
1
0
Figure 22-13. Rewriting Entire Memory Area (Boot Swap)
Rewriting blocks
2 and 3
CHAPTER 22 FLASH MEMORY
User’s Manual U16543EJ4V0UD
Block
Block
Block
Block
3
2
1
0
Boot swap
Block
Block
Block
Block
3
2
1
0