HD64F2149YV datasheet(747/1075 Pages) RENESAS

747 / 1075 page

Section 22 ROM

Rev. 3.00 Jan 18, 2006 page 719 of 1044

REJ09B0280-0300

22.9

Interrupt Handling when Programming/Erasing Flash Memory

All interrupts, including NMI input 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*

to give priority to the program or erase operation. There are three reasons for this:

1. Interrupt during programming or erasing might cause a violation of the programming or

erasing algorithm, with the result that normal operation could not be assured.

2. In the interrupt exception handling sequence during programming or erasing, the vector would

not be read correctly*

2, possibly resulting in MCU runaway.

3. If interrupt occurred during boot program execution, it would not be possible to execute the

normal boot mode sequence.

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 interrupt requests, including NMI input, must

therefore be disabled inside and outside the MCU when programming or erasing flash memory.

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

control program has completed programming.

2. The vector may not be read correctly in this case for the following two reasons:

•

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.

22.10

Flash Memory Programmer Mode

22.10.1

Programmer Mode Setting

Programs and data can be written and erased in programmer mode as well as in the on-board

programming modes. In programmer mode, the on-chip ROM can be freely programmed using a

PROM programmer that supports Renesas Technology microcomputer device types with 64-kbyte

on-chip flash memory*. For precautions concerning the use of programmer mode, see section

22.10.10, Notes on Memory Programming and section 22.11, Flash Memory Programming and

Erasing Precausions. Flash memory read mode, auto-program mode, auto-erase mode, and status

read mode are supported with these device types. In auto-program mode, auto-erase mode, and

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