HD6412320 RENESAS [Renesas Technology Corp], HD6412320 Datasheet - Page 919

• Manufacturer Part Number: HD6412320
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family H8S-2300 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

19.28
All interrupts, including NMI input, are disabled when flash memory is being programmed or
erased (when the P1 or E1 bit is set in FLMCR1, or the P2 or E2 bit is set in FLMCR2), and while
the boot program is executing in boot mode *
There are three reasons for this:
1. Interrupt during programming or erasing might cause a violation of the programming or
2. In the interrupt exception handling sequence during programming or erasing, the vector would
3. If an interrupt occurred during boot program execution, it would not be possible to execute the
For these reasons, in on-board programming mode alone there are conditions for disabling
interrupts, as an exception to the general rule. However, this provision does not guarantee normal
erasing and programming or MCU operation. All requests, including NMI, must therefore be
restricted inside and outside the MCU when programming or erasing flash memory. The NMI
interrupt is also disabled in the error-protection state while the P1 or E1 bit remains set in
FLMCR1, or the P2 or E2 bit remains set in FLMCR2.
Notes: 1. Interrupt requests must be disabled inside and outside the MCU until the programming
erasing algorithm, with the result that normal operation could not be assured.
not be read correctly *
normal boot mode sequence.
2. A RAM area cannot be erased by execution of software in accordance with the erase
3. Block area EB0 includes the vector table. When performing RAM emulation, the
2. The vector may not be read correctly in this case for the following two reasons:
Interrupt Handling when Programming/Erasing Flash Memory
the P2 or E2 bit in FLMCR2 will not cause a transition to program mode or erase
mode. When actually programming a flash memory area, the RAMS bit should be
cleared to 0.
algorithm while flash memory emulation in RAM is being used.
vector table is needed by the overlap RAM.
control program has completed programming.
•
•
If flash memory is read while being programmed or erased (while the P1 or E1 bit
is set in FLMCR1, or the P2 or E2 bit is set in FLMCR2.), correct read data will not
be obtained (undetermined values will be returned).
If the interrupt entry in the vector table has not been programmed yet, interrupt
exception handling will not be executed correctly.
2
, possibly resulting in MCU runaway.
1
, to give priority to the program or erase operation.
Rev.6.00 Sep. 27, 2007 Page 889 of 1268
REJ09B0220-0600
Section 19 ROM