M16C26A Datasheet, PDF (320/352 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/Tiny SERIES

M16C/26A Group (M16C/26A, M16C/26B, M16C/26T)
19. Usage Notes
19.4 Protect
Set the PRC2 bit to “1” (write enabled) and then write to any address, and the PRC2 bit will be cleared to “0”
(write protected). The registers protected by the PRC2 bit should be changed in the next instruction after
setting the PRC2 bit to “1”. Make sure no interrupts or DMA transfers will occur between the instruction in
which the PRC2 bit is set to “1” and the next instruction.
Rev. 2.00 Feb.15, 2007 ^{page 303} of 329
REJ09B0202-0200