HD64F3437TF16 Datasheet, PDF (507/752 Pages) Hitachi Semiconductor – 12 V must not be applied to the S-mask model (single-power-supply specification), as this may permanently damage the device.

Example of Emulation of Real-Time Flash-Memory Update
H'0000
Small-block
area (SB1)
H'007F
H'0080
H'00FF
H'0100
Overlapped RAM
Flash memory
address space
H'F77F
H'F780
Overlapped _H'F880
RAM
H'F8FF
H'FF7F
On-chip
RAM area
Procedure
1. Overlap part of RAM (H'F880 to H'F8FF) onto the area requiring real-time update (SB1).
(Set WSCR bits 7 and 6 to 01.)
2. Perform real-time updates in the overlapping RAM.
3. After finalization of the update data, clear the RAM overlap (by clearing the RAMS and RAM0
bits).
4. Read the data written in RAM addresses H'F880 to H'F8FF out externally, then program the
flash memory area, using this data as part of the program data.
Figure 20.12 Example of RAM Overlap
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