M16C30P_07 Datasheet, PDF (215/317 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/30 SERIES

M16C/30P Group
19. Flash Memory Version
19.2.3 Forced Erase Function
This function is available only in standard serial I/O mode.
When the reserved characters, “A”, “L”, “e”, “R”, “A”, “S”, and “E” in ASCII code, are sent from the serial
programmer as ID codes, the content of the user ROM area will be erased at once. However, if the ID codes
stored in the ID code addresses in the user ROM area are set to other than a reserved word “ALeRASE” (other
than the combination table listed in Table 19.3) when the ROMCP bit in the ROMCP address is set to other than
11b (ROM code protect enabled), forced erase function is ignored and ID code check is executed. Table 19.4
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 addresses
correspond to the reserved word ALeRASE”, the user ROM area will be erased. However, when the serial
programmer sends other than “ALeRASE”, even if the ID codes stored in the ID code addresses are
“ALeRASE”, there is no ID match and any command is ignored. The user ROM area remains protected
accordingly.
Table 19.4 Forced Erase Function
ID code from
serial program-
mer
ALeRASE
Other than
ALeRASE
Condition
Code in ID code
stored address
ROMCP1 bit in the
ROMCP address
Function
ALeRASE
Other than
ALeRASE
ALeRASE
Other than
ALeRASE
−
11b (ROM code pro-
tect disabled)
00b, 01b, 10b (ROM
code protect enabled)
−
−
User ROM area all erase (forced erase
function)
ID code check
ID code check (no ID match)
ID code check
Rev.1.22 Mar 29, 2007 Page 199 of 291
REJ09B0179-0122