HD64F3039F18 Datasheet, PDF (514/710 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8 Family / H8/300H Series

Section 15 ROM
• Apply an input to FWE when the program is not running away.
When applying an input to the FWE pin, the program execution state must be supervised
using a watchdog timer, etc.
• Input low level to the FWE pin when the SWE, ESU, PSU, EV, PV, E, and P bits in
FLMCR have been cleared.
Do not erroneously set the SWE, ESU, PSU, EV, PV, E, and P bits when FWE High/Low.
(4) Do not input a constant high level to the FWE pin.
To prevent erroneous programming/erasing in the event of program runaway, etc., input a high
level to the FWE pin only when programming/erasing flash memory (including flash memory
emulation by RAM). Avoid system configurations that constantly input a high level to the
FWE pin. Handle program runaway, etc. by starting the watchdog timer so that flash memory
is not overprogrammed/overerased even while a high level is input to the FWE pin.
(5) Program/erase the flash memory in accordance with the recommended algorithms.
The recommended algorithms can program/erase the flash memory without applying voltage
stress to the device or sacrificing the reliability of the program data.
When setting the PSU and ESU bits in FLMCR, set the watchdog timer for program runaway,
etc.
(6) Do not set/clear the SWE bit while a program is executing on flash memory.
Before performing flash memory program execution or data read, clear the SWE bit.
If the SWE bit is set, the flash data can be reprogrammed, but flash memory cannot be
accessed for purposes other than verify (verify during programming/erase).
Similarly perform flash memory program execution and data read after clearing the SWE bit
even when using the RAM emulation function with a high level input to the FWE pin.
However, RAM area that overlaps flash memory space can be read/programmed whether the
SWE bit is set or cleared.
(7) Do not use an interrupt during flash memory programming or erasing.
Since programming/erase operations (including emulation by RAM) have priority when a high
level is input to the FWE pin, disable all interrupt requests, including NMI.
(8) Do not perform additional programming. Reprogram flash memory after erasing.
With on-board programming, program to 32-byte programming unit blocks one time only.
Program to 128-byte programming unit blocks one time only even in the PROM mode. Erase
all the programming unit blocks before reprogramming.
Bus release must also be disabled.
Rev.3.00 Mar. 26, 2007 Page 490 of 682
REJ09B0353-0300