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21.10.10
Notes On Memory Programming
When programming addresses which have previously been programmed, carry out auto-
erasing before auto-programming.
When performing programming using writer mode on a chip that has been
programmed/erased in an on-board programming mode, auto-erasing is recommended before
carrying out auto-programming.
Notes: 1. The flash memory is initially in the erased state when the device is shipped by
Hitachi. For other chips for which the erasure history is unknown, it is recommended
that auto-erasing be executed to check and supplement the initialization (erase) level.
2. Auto-programming should be performed once only on the same address block.
21.11
Flash Memory Programming and Erasing Precautions
Precautions concerning the use of on-board programming mode and writer mode are
summarized below.
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
Hitachi microcomputer device types with 128-kbyte or 64-kbyte on-chip flash memory.
Do not select the HN28F101 setting for the PROM programmer, and only use the specified
socket adapter. Incorrect use will result in damaging the device.
Powering on and off: When applying or disconnecting V
CC, 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.
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.
Do not set or clear the SWE bit during program execution in flash memory: Clear 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, but flash memory should only be accessed for verify
operations (verification during programming/erasing).
Do not use interrupts while flash memory is being programmed or erased: All interrupt
requests, including NMI, should be disabled to give priority to program/erase operations.