UPD78F0838 Renesas Electronics Corporation., UPD78F0838 Datasheet - Page 824

• Manufacturer Part Number: UPD78F0838
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

26.10 Flash Memory Programming by Self-Programming
program. Because this function allows a user application to rewrite the flash memory by using the 78K0/Dx2 self-
programming library, it can be used to upgrade the program in the field.
servicing can be executed. To execute interrupt servicing, restore the normal operation mode after self-programming
has been stopped, and execute the EI instruction.
programming can be resumed.
822
The 78K0/Dx2 supports a self-programming function that can be used to rewrite the flash memory via a user
If an interrupt occurs during self-programming, self-programming can be temporarily stopped and interrupt
(Caution 6 is listed on the next page.)
Remark For details of the self-programming function and the 78K0/Dx2 self-programming library, refer to a
Cautions 1. The self-programming function cannot be used when the CPU operates with the subsystem
separate document to be published (document name: 78K0/Dx2 Application Note, release schedule:
Pending).
2. Input a high level to the FLMD0 pin during self-programming.
3. Be sure to execute the DI instruction before starting self-programming.
4. Self-programming is also stopped by an interrupt request that is not masked even in the DI
5. Self-programming is executed with the internal high-speed oscillation clock. If the CPU
clock.
The self-programming function checks the interrupt request flags (IF0L, IF0H, IF1L, and
IF1H). If an interrupt request is generated, self-programming is stopped.
status. To prevent this, mask the interrupt by using the interrupt mask flag registers (MK0L,
MK0H, MK1L, and MK1H).
operates with the X1 clock or external main system clock, the oscillation stabilization wait
time of the internal high-speed oscillation clock elapses during self-programming.
Preliminary User’s Manual U19748EJ1V0UD
CHAPTER 26 FLASH MEMORY
After the self-programming mode is later restored, self-