HD64F2357F20V Datasheet, PDF (677/1049 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-chip Microcomputer H8S Family / H8S/2300 Series

19.21 Interrupt Handling when Programming/Erasing Flash Memory
All interrupts, including NMI input, are 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, 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 an 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 interrupts, 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, 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 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.
19.22 Flash Memory Programmer Mode
19.22.1 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 the Renesas
Technology microcomputer device type with 256-kbyte on-chip flash memory (FZTAT256V5A). Flash memory read
mode, auto-program mode, auto-erase mode, and status read mode are supported with this device type. 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.
Table 19-39 shows programmer mode pin settings.
Table 19-39 Programmer Mode Pin Settings
Pin Names
Mode pins: MD2, MD1, MD0
Mode setting pins: P66, P65, P64
STBY pin
RES pin
XTAL, EXTAL pins
Other pins requiring setting: P32, P25
Settings/External Circuit Connection
Low-level input
High-level input to P66, low-level input to P65 and P64
High-level input (do not select hardware standby mode)
Reset circuit
Oscillator circuit
High-level input to P32, low-level input to P25
Rev.6.00 Oct.28.2004 page 647 of 1016
REJ09B0138-0600H