Renesas R8C series, Hardware Manual

Page: 187 / 257

R8C/18 Group, R8C/19 Group 17. Flash Memory Version
Rev.1.30 Apr 14, 2006 Page 172 of 233
REJ09B0222-0130
17. Flash Memory Version
17.1 Overview
In the flash memory version, rewrite operations to the flash memory can be performed in three modes
;
CPU rewrite, standard serial I/O, and parallel I/O.
Table 17.1 lists the Flash Memory Version Performance (refer to
Table 1.1 Functions and
Specifications for R8C/18 Group and Table 1.2 Functions and Specifications for R8C/19 Group for
items not listed in Table 17.1).
NOTES:
1. Definition of programming and erasure endurance
The programming and erasure endurance is defined on a per-block basis. If the programming and
erasure endurance is n (n = 100 or 10,000), each block can be erased n times. For example, if 1,024
1-byte writes are performed to block A, a 1-Kbyte block, and then the block is erased, the erase
count stands at one. When performing 100 or more rewrites, the actual erase count can be reduced
by executing programming operations in such a way that all blank areas are used before performing
an erase operation. Avoid rewriting only particular blocks and try to average out the programming
and erasure endurance of the blocks. It is also advisable to retain data on the erase count of each
block and limit the number of erase operations to a certain number.
2. Blocks A and B are implemented only in the R8C/19 Group.
Table 17.1 Flash Memory Version Performance
Item Specification
Flash memory operating mode 3 modes (CPU rewrite, standard serial I/O, and parallel I/O mode)
Division of erase block Refer to Figure 17.1 and Figure 17.2
Programming method Byte unit
Erase method Block erase
Programming and erasure
control method Program and erase control by software command
Rewrite control method Rewrite control for blocks 0 and 1 by FMR02 bit in FMR0 register.
Rewrite control for block 0 by FMR15 bit and block 1 by FMR16 bit in
FMR1 register.
Number of commands 5 commands
Programming
and erasure
endurance
(1)
Blocks 0 and 1
(program ROM) R8C/18 Group: 100 times; R8C/19 Group: 1,000 times
Blocks A and B
(data flash)
(2)
10,000 times
ID code check function Standard serial I/O mode supported
ROM code protect Parallel I/O mode supported