Table of Contents
Advertisement
R8C/18 Group, R8C/19 Group
17.3
Functions to Prevent Rewriting of Flash Memory
Standard serial I/O mode has an ID code check function, and parallel I/O mode has a ROM code protect
function to prevent the flash memory from being read or rewritten easily.
17.3.1
ID Code Check Function
This function is used in standard serial I/O mode. Unless the flash memory is blank, the ID codes sent
from the programmer and the ID codes written in the flash memory are checked to see if they match.
If the ID codes do not match, the commands sent from the programmer are not acknowledged. The
ID codes consist of 8 bits of data each, the areas of which, beginning with the first byte, are 00FFDFh,
00FFE3h, 00FFEBh, 00FFEFh, 00FFF3h, 00FFF7h, and 00FFFBh. Write programs in which the ID
codes are set at these addresses and write them to the flash memory.
Figure 17.3
Address for Stored ID Code
Rev.1.30
Apr 14, 2006
REJ09B0222-0130
Address
00FFDFh to 00FFDCh
00FFE3h to 00FFE0h
00FFE7h to 00FFE4h
00FFEBh to 00FFE8h
00FFEFh to 00FFECh
00FFF3h to 00FFF0h
00FFF7h to 00FFF4h
00FFFBh to 00FFF8h
00FFFFh to 00FFFCh
(Note 1)
NOTE:
1. The OFS register is assigned to 00FFFFh. Refer to
Figure 13.2 Registers OFS and WDC and Figure
13.3 Registers WDTR and WDTS for OFS register
details.
Page 176 of 233
ID1
Undefined instruction vector
ID2
Overflow vector
BRK instruction vector
ID3
Address match vector
ID4
Single step vector
Oscillation stop detection/watchdog
ID5
timer/voltage monitor 2 vector
ID6
Address break
ID7
(Reserved)
Reset vector
4 bytes
17. Flash Memory Version
Advertisement
Table of Contents
