upd70f3422gj-gae-qs-ax Renesas Electronics Corporation., upd70f3422gj-gae-qs-ax Datasheet - Page 234

• Manufacturer Part Number: upd70f3422gj-gae-qs-ax
• Description: 32-bit Single-chip Microcontroller
• Manufacturer: Renesas Electronics Corporation.

Chapter 6
234
programming
Start of self-
Table 6-1
Caution
6.2.1 Flash self-programming registers
6.2 Flash Self-Programming
The internal flash memory can be programmed via the secure self-program-
ming facility. This feature enables the user’s application to re-program the flash
memory. The self-programming functions are part of the internal firmware,
which resides in an extra internal ROM. The user’s application can call the self-
programming functions via the self-programming library, provided by NEC.
During self-programming make sure to disable all ROM correction facilities, as
enabled ROM corrections may conflict with the internal firmware.
The self-programming functions can be started out of the normal user mode of
the microcontroller.
Self-programming must be in particular enabled in order to avoid unintended
re-programming of the flash. Two ways to enable self-programming are
provided:
• by setting the external FLMD0 pin to high level
• by setting an internal register bit
The following registers are used to enable self-programming internally by
software.
For safety reasons flash self-programming needs to be explicitly enabled by
use of two registers:
Flash self-programming enable register overview
Preliminary User’s Manual U17566EE1V2UM00
Register name
Self-programming enable control register
Self-programming enable protection register
This requires some external components or wiring, e.g. connecting an
output port to FLMD0.
This way does not need any special external components or wiring.
Shortcut
SELFEN
SELFENP
Flash Memory
Address
FFFF FCA0
FFFF FCA8
H
H