HD64F2636F20 Datasheet, PDF (839/1512 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2600 Series

H8S/2639, H8S/2638, H8S/2636,
H8S/2630, H8S/2635 Group
Section 21A ROM
(H8S/2636 Group)
2. In a power-down state, FLMCR1, FLMCR2, EBR1, EBR2, RAMER, and FLPWCR cannot be
read from or written to.
21A.15 Flash Memory Programming and Erasing Precautions
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 Electronics microcomputer device type with 128-kbyte
on-chip flash memory.
Only use the specified socket adapter. Failure to observe these points may result in damage to
the device.
2. Powering on and off (see figures 21A-18 to 21A-20)
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.
3. FWE application/disconnection (see figures 21A-18 to 21A-20)
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 V_CC voltage has stabilized within its rated voltage range.
Apply FWE when oscillation has stabilized (after the elapse of the oscillation settling
time).
• 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 a
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.
REJ09B0103-0800 Rev. 8.00
May 28, 2010
Page 789 of 1458