Hitachi H8S/2378, H8S/2378R Series Hardware Manual page 834

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 5(6 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. Use the recommended algorithm when programming and erasing flash memory.
The recommended algorithm enables programming and erasing to be carried out without
subjecting the device to voltage stress or sacrificing program data reliability. When setting the
P or E bit in FLMCR1, the watchdog timer should be set beforehand as a precaution against
program runaway, etc.
4. Do not set or clear the SWE bit during execution of a program in flash memory.
Wait for at least 100 µs after clearing the SWE bit before executing a program or reading data
in flash memory.
When the SWE bit is set, data in flash memory can be rewritten. When the SWE bit is set to 1,
data in flash memory can be read only in program-verify/erase-verify mode. Access flash
memory only for verify operations (verification during programming/erasing). Also, do not
clear the SWE bit during programming, erasing, or verifying. Similarly, when using the RAM
emulation function, the SWE bit must be cleared before executing a program or reading data in
flash memory.
However, the RAM area overlapping flash memory space can be read and written to regardless
of whether the SWE bit is set or cleared.
5. Do not use interrupts while flash memory is being programmed or erased.
All interrupt requests, including NMI, should be disabled during programming/erasing the
flash memory to give priority to program/erase operations.
6. Do not perform additional programming. Erase the memory before reprogramming.
In on-board programming, perform only one programming operation on a 128-byte
programming unit block. In programmer mode, too, perform only one programming operation
on a 128-byte programming unit block. Programming should be carried out with the entire
programming unit block erased.
7. Before programming, check that the chip is correctly mounted in the PROM programmer.
Overcurrent damage to the device can result if the index marks on the PROM programmer
socket, socket adapter, and chip are not correctly aligned.
8. Do not touch the socket adapter or chip during programming.
Touching either of these can cause contact faults and write errors.
9. Apply the reset signal after the SWE, bit is cleared during its operation.
The reset signal is applied at least 100 µs after the SWE bit has been cleared.
Rev. 1.0, 09/01, page 790 of 904