Datasheet
Section 19 Flash Memory (F-ZTAT Version)
Rev. 3.00 Mar 17, 2006 page 802 of 926
REJ09B0283-0300
19.12 Usage Notes
Precautions concerning the use of on-board programming mode, the RAM emulation function, and
programmer mode are summarized below.
1. 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 the Renesas Technology microcomputer device type with 512-kbyte
on-chip flash memory (FZTAT512V3A).
Do not select the HN27C4096 setting for the PROM programmer, and only use the specified
socket adapter.
2. Reset the flash memory before turning on/off the power.
When applying or disconnecting Vcc power, fix the RES 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.
3. Powering on and off.
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
power, 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. The power-on and power-off timing in the H8S/2678
Group is shown in figure 19.12.
4. FWE application/disconnection.
FWE application should be carried out when this LSI operation is in a stable condition. If this
LSI operation is not stable, fix the FWE pin low and set the protection state.
The following points must be observed concerning FWE application and disconnection to prevent
unintentional programming or erasing of flash memory:
• Apply FWE when the V
CC
voltage has stabilized within its rated voltage range.
• In boot mode, apply and disconnect FWE during a reset.
• In user program mode, FWE can be switched between high and low level regardless of the
reset state. FWE input can also be switched during execution of a program in flash memory.
• Do not apply FWE if program runaway has occurred.
• Disconnect FWE only when the SWE, ESU, PSU, EV, PV, and E bits in FLMCR1 are cleared.