HD6432646 Hitachi, HD6432646 Datasheet - Page 729

• Manufacturer Part Number: HD6432646
• Description: (HD64F264x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

20.10
All interrupts, including NMI interrupt is disabled when flash memory is being programmed or
erased (when the P or E bit is set in FLMCR1), and while the boot program is executing in boot
mode
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 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
interrupt, as an exception to the general rule. However, this provision does not guarantee normal
erasing and programming or MCU operation. All requests, including NMI interrupt, must
therefore be restricted inside and outside the MCU when programming or erasing flash memory.
NMI interrupt is also disabled in the error-protection state while the P or E bit remains set in
FLMCR1.
Notes: *1 Interrupt requests must be disabled inside and outside the MCU until the programming
20.11
Programs and data can be written and erased in programmer mode as well as in the on-board
programming modes. In programmer mode, flash memory read mode, auto-program mode, auto-
erase mode, and status read mode are supported. In auto-program mode, auto-erase mode, and
status read mode, a status polling procedure is used, and in status read mode, detailed internal
signals are output after execution of an auto-program or auto-erase operation.
In programmer mode, set the mode pins to programmer mode (see table 20-9) and input a 12 MHz
input clock.
Table 20-9 shows the pin settings for programmer mode. For the pin names in programmer mode,
see figure 20-17.
erasing algorithm, with the result that normal operation could not be assured.
not be read correctly
normal boot mode sequence.
*1
, to give priority to the program or erase operation. There are three reasons for this:
*2 The vector may not be read correctly in this case for the following two reasons:
Interrupt Handling when Programming/Erasing Flash Memory
Flash Memory Programmer Mode
control program has completed programming.
•
•
If flash memory is read while being programmed or erased (while the P or E bit is
set in FLMCR1), 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.
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