HD6432345 Datasheet, PDF (615/907 Pages) Hitachi Semiconductor – H8S/2345 F-ZTAT Hardware Manual

Reprogramming an address that
has already been programmed
Auto-erase
(all of flash memory)
Auto-program
End
Figure 17.35 Reprogramming an Address that has Already Been Programmed
17.14 Flash Memory Programming and Erasing Precautions
Precautions concerning the use of on-board programming mode, the RAM emulation function, and
writer mode are summarized below.
Use the specified voltages and timing for programming and erasing: Applied voltages in
excess of the rating can permanently damage the device. Use a PROM programmer that supports
Hitachi microcomputer device types with 128-kbyte on-chip flash memory.
Do not select the HN28F101 setting for the PROM programmer, and only use the specified socket
adapter. Incorrect use will result in damaging the device.
Powering on and off (see figures 17.36 to 17.38): Do not apply a high level to the FWE pin until
V_CC has stabilized. Also, drive the FWE pin low before turning off V_CC.
When applying or disconnecting V_CC, fix the FWE pin low and place the flash memory in the
hardware protection state.
The power-on and power-off timing requirements should also be satisfied in the event of a power
failure and subsequent recovery. If these timing requirements are not satisfied, the microcomputer
experience program runaway, possibly resulting in excessive programming and erasing that could
cause the memory cell to no longer operate properly.
FWE pin application/disconnection (see figure 19.36 to figure 19.38): FWE pin application
should be carried out when MCU operation is in a stable condition. If MCU operation is not
stable, fix the FWE pin low and set the protection state.
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