HD64F3028F25 Datasheet, PDF (648/925 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series

18.10.2 Notes on Use of PROM Mode
1. A write to a 128-byte programming unit in PROM mode should be performed once only.
Erasing must be carried out before reprogramming an address that has already been
programmed.
2. When using a PROM writer to reprogram a device on which on-board programming/erasing
has been performed, it is recommended that erasing be carried out before executing
programming.
3. The memory is initially in the erased state when the device is shipped by Renesas Technology.
For samples for which the erasure history is unknown, it is recommended that erasing be
executed to check and correct the initialization (erase) level.
4. The H8/3028F-ZTAT does not support a product identification mode as used with general-
purpose EPROMs, and therefore the device name cannot be set automatically in the PROM
writer.
5. Refer to the instruction manual provided with the socket adapter, or other relevant
documentation, for information on PROM writers and associated program versions that are
compatible with the PROM mode of the H8/3028F-ZTAT.
18.11 Flash Memory Programming and Erasing Precautions
Precautions concerning the use of on-board programming mode, the RAM emulation function, and
PROM 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 microcomputer device type “F-ZTAT512” with 512-
kbyte on-chip flash memory.
2. Powering on and off (see figures 18.16 to 18.18)
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. Failure to do so may result in overprogramming or
overerasing due to MCU runaway, and loss of normal memory cell operation.
3. 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:
Rev. 2.00, 09/03, page 616 of 890