Flash Memory Emulation In Ram - Hitachi H8S/2378, H8S/2378R Series Hardware Manual

20.7

Flash Memory Emulation in RAM

Making a setting in the RAM emulation register (RAMER) enables RAM to be overlapped onto
the part of flash memory area so that data to be programmed to flash memory can be emulated in
the on-chip RAM in real time. Emulation can be performed in user mode or user program mode.
Figure 20.7 shows an example of emulation of real-time flash memory programming.
1. Set RAMER to overlap RAM onto the area for which real-time programming is required.
2. Emulation is performed using the overlapping RAM.
3. After the program data has been confirmed, the RAMS bit is cleared, thus releasing RAM
overlap.
4. The data written in the overlapping RAM is written into the flash memory space (EB0).
Figure 20.7 Flowchart for Flash Memory Emulation in RAM
Example in which flash memory block is overlapped is shown in figure 20.8.
1. The RAM area to be overlapped is fixed at a 4-kbyte area in the range of H'FFA000 to
H'FFAFFF.
2. The flash memory area to overlap is selected by RAMER from a 4-kbyte area among one of
the EB0 to EB7 blocks.
Rev. 1.0, 09/01, page 782 of 904
Start of emulation program
Set RAMER
Write tuning data to overlap
RAM
Execute application program
No
Tuning OK?
Yes
Clear RAMER
Write to flash memory
emulation block
End of emulation program