M16C65 Datasheet, PDF (769/829 Pages) Renesas Technology Corp – RENESAS MCU M16C FAMILY / M16C/60

Under development
M16C/65 Group
Preliminary Specification
This is a preliminary specification and is subject to change.
30. Flash Memory
30.9.2 Forced Erase Function
Use the forced erase function in standard serial I/O mode. When the reserved word, “ALeRASE” in
ASCII code, are sent from the serial programmer as ID codes, the contents of program ROM 1 and
program ROM 2 will be erased at once. However, if the ID codes stored in the ID code storage
addresses are set to other than a reserved word “ALeRASE” (other than the combination table listed in
Table 30.17) when the ROMCP1 bit in the OFS1 address is set to 0 (ROM code protect enabled),
forced erase function is ignored and ID code check is executed by ID code check function. Table 30.18
lists conditions and functions for forced erase function.
When both the ID codes sent from the serial programmer and the ID codes stored in the ID code
storage addresses correspond to the reserved word “ALeRASE”, program ROM 1 and program ROM 2
will be erased. However, when the serial programmer sends other than “ALeRASE”, even if the ID
codes stored in the ID code storage addresses are “ALeRASE”, there is no ID match and any
command is ignored. The flash memory cannot be operated.
Table 30.18 Forced Erase Function
Condition
ID code from serial Code in ID code ROMCP1 bit in the
Function
programmer
storage address
OFS1 address
ALeRASE
ALeRASE
–
Program ROM 1 and program ROM 2
Other than
ALeRASE ⁽¹⁾
1 (ROM code
protect disabled)
all erase
(forced erase function)
0 (ROM code protect ID code check (ID code check function)
enabled)
Other than
ALeRASE
–
ID code check (ID code check function.
ALeRASE
No ID match)
Other than
–
ID code check (ID code check function)
ALeRASE ⁽¹⁾
Note:
1. For the combination of the stored addresses is “Protect”, refer to 30.9.3 “Standard Serial I/O
Mode Disable Function”.
30.9.3 Standard Serial I/O Mode Disable Function
Use the standard serial I/O mode disable function in standard serial I/O mode. When the ID codes in
the ID code stored addresses are set to “Protect” in ASCII code (refer to Table 30.17 “Reserved Word
of ID Code”), the MCU does not communicate with the serial programmer. Therefore, the flash memory
cannot be read, written or erased by the serial programmer. User boot mode can be selected, when the
ID codes are set to “Protect”.
When the ID codes are set to “Protect” and the ROMCP1 bit in the OFS1 address is set to 0 (ROM
code protect enabled), ROM code protection cannot be disabled by the serial programmer. Therefore,
the flash memory cannot be read, written or erased by the serial or parallel programmer.
REJ09B0484-0030 Rev.0.30 Sep 09, 2008
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