INTERNAL MEMORY
6.9 Precautions To Be Taken when Rewriting the Internal Flash Memory
6
6.9 Precautions To Be Taken when Rewriting the Internal Flash Memory
The following describes precautions to be taken when programming/erasing the internal flash memory.
• When the internal flash memory is programmed or erased, a high voltage is generated internally. Because mode
transitions during programming/erase operation may cause the chip to break down, make sure the mode setting
pin/power supply voltages do not fluctuate to prevent unintended changes of modes.
• If the system uses any pins that are to be used by a general-purpose programming/erase tool, care must be
taken to prevent adverse effects on the system when the tool is connected.
• If the internal flash memory needs to be protected while using a general-purpose programming/erase tool, set
any ID in the flash memory protect ID verification area (H’0000 0084 to H’0000 008F).
• If the internal flash memory does not need to be protected while using a general-purpose programming/erase
tool, fill the entire flash memory protect ID verification area (H’0000 0084 to H’0000 008F) with H’FF.
• If the Flash Status Register 2 (FSTAT2)’s each error status is to be cleared (initialized to H’80) by resetting the
Flash Control Register 4 (FCNT4) FRESET bit, check to see that the Flash Status Register 1 (FSTAT1) FSTAT
bit = "1" (ready) before clearing the error status.
• Before resetting the Flash Control Register 1 (FCNT1) FENTRY bit from "1" to "0", check to see that the Flash
Status Register 1 (FSTAT1) FSTAT bit = "1" (ready) or the Flash Status Register 2 (FSTAT2) FBUSY bit = "1"
(ready).
• Do not clear the FENTRY bit if the Flash Status Register 1 (FSTAT1) FSTAT bit = "0" (busy) or the Flash Status
Register 2 (FSTAT2) FBUSY bit = "0" (being programmed or erased).
32180 Group User’s Manual (Rev.1.0)
6-39
RENESAS [ RENESAS TECHNOLOGY CORP ]
