RX610 Group
26. ROM (Flash Memory for Code Storage)
R01UH0032EJ0120 Rev.1.20
Page 905 of 1006
Feb 20, 2013
26.13 Usage Notes
(1) Areas where Programming or Erasure is Suspended
Data in areas where programming or erasure is suspended are undefined. To avoid malfunctions due to the reading of
undefined data, prevent the reading of data and execution of code from areas where programming or erasure is currently
suspended.
(2) Suspending Programming or Erasure
If you use the programming/erasure suspension command to suspend the processing of programming or erasure, be
sure to use the resumption command so that the processing is completed. Within 20μs (when PCLK = 50 MHz) after
issuance of the resumption command, the programming/erasure suspension command should not be issued again.
(3) Prohibition of Reprogramming
Two or more programming operations cannot be performed for the same address range. If an address range that has
already been programmed is to be programmed again, be sure to erase the area in advance of the programming.
(4) Reset during Programming or Erasure
Do not apply the active level to the RES# pin during programming or erasure because a reset may damage the flash
memory. If the reset signal is erroneously input, only deassert the signal after assertion of the signal within the range of
operating voltage specified in the Electrical Characteristics has continued for at least 100 μs.
If programming or erasure is proceeding and the FRESET bit in FRESETR is used to reset the FCU , make sure that
the reset state is maintained over the period tRESW2 (see section 29, Electrical Characteristics). Do not attempt to read a
target ROM for programming or erasure during the period of an FCU reset.
A WDT reset, however, can be applied even during programming or erasure regardless of the time to be secured that
was described above.
(5) Prohibition of Non-Maskable Interrupts during Programming or Erasure
A non-maskable interrupt (an interrupt on the NMI pin) during programming or erasure will lead to fetching of the
vector from the ROM, and the data read out will be undefined. Ensure that non-maskable interrupts are not generated
during programming or erasure of the ROM. (This restriction only applies to the ROM).
(6) Interrupt Vector Assignment During Programming or Erasure
The generation of interrupts during programming or erasure may lead to the fetching of vectors from the ROM. To
prevent access to the ROM area due to the generation of interrupts, set the interrupt table register (INTB) of the CPU so
that the destination for the fetching of interrupt vector is an area outside the ROM.
(7) Abnormal Termination during Programming or Erasure
If a failure in programming or erasure is caused by a voltage beyond the specified range of operating voltage, a reset,
an FCU reset by the FRESETR.FRSET bit, entry to the command-locked state due to error detection, or either of the
prohibited items under (8), the lock bit may be set to 0 (protected). In this case, set the FPROTR.FPROTCN bit to 1 to
issue a block erase command and erase the lock bit. After this, proceed with the failed programming or erasure again.
Summary of Contents for RX600 Series
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