h8s-2649 Renesas Electronics Corporation., h8s-2649 Datasheet - Page 594

• Manufacturer Part Number: h8s-2649
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

Section 19 ROM
19.13
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 256-kbyte flash memory on-chip microcomputer device type (FZTAT256V3A).
Do not select the HN27C4096 setting for the PROM programmer, and only use the specified
socket adapter. Failure to observe these points may result in damage to the device.
Powering on and off: Do not apply a high level to the FWE pin until VCC has stabilized. Also,
drive the FWE pin low before turning off VCC.
When applying or disconnecting VCC 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.
FWE application/disconnection: FWE 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.
The following points must be observed concerning FWE application and disconnection to prevent
unintentional programming or erasing of flash memory:
• Apply FWE when the VCC 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
• Do not apply FWE if program runaway has occurred.
• Disconnect FWE only when the SWE, ESU, PSU, EV, PV, P, and E bits in FLMCR1 are
Do not apply a constant high level to the FWE pin: Apply a high level to the FWE pin only
when programming or erasing flash memory. A system configuration in which a high level is
constantly applied to the FWE pin should be avoided. Also, while a high level is applied to the
FWE pin, the watchdog timer should be activated to prevent overprogramming or overerasing due
to program runaway, etc.
Rev. 2.00 Dec. 05, 2005 Page 556 of 724
REJ09B0200-0200
reset state. FWE input can also be switched during execution of a program in flash memory.
cleared.
Make sure that the SWE, ESU, PSU, EV, PV, P, and E bits are not set by mistake when
applying or disconnecting FWE.
Usage Notes