R8C/20 Group, R8C/21 Group 20. Electrical Characteristics
Rev.2.00 Aug 27, 2008 Page 411 of 458
REJ09B0250-0200
NOTES:
1. V
CC = 2.7 to 5.5 V at Topr = -40 to 85°C (J version) / -40 to 125°C (K version), unless otherwise specified.
2. Definition of programming/erasure endurance
The programming and erasure endurance is defined on a per-block basis.
If the programming and erasure endurance is n (n = 10,000), each block can be erased n times.
For example, if 1,024 1-byte writes are performed to different addresses in block A, a 1 Kbyte block, and then the block is
erased, the programming/erasure endurance still stands at one. However, the same address must not be programmed more
than once per erase operation (overwriting prohibited).
3. MInimum endurance to guarantee all electrical characteristics after program and erase (1 to Min. value can be guaranteed).
4. Standard of block A and block B when program and erase endurance exceeds 1,000 times. Byte program time to 1,000 times
are the same as that in program ROM.
5. In a system that executes multiple programming operations, the actual erasure endurance can be reduced by writing to
sequential addresses in turn so that as much of the block as possible is used up before performing an erase operation. For
example, when programming groups of 16 bytes, the effective number of rewrites can be minimized by programming up to
128 groups before erasing them all in one operation. In addition, averaging the erasure endurance between blocks A and B
can further reduce the actual erasure endurance. It is also advisable to retain data on the erasure endurance of each block
and limit the number of erase operations to a certain number.
6. If error occurs during block erase, attempt to execute the clear status register command, then the block erase command at
least three times until the erase error does not occur.
7. Customers desiring program/erase failure rate information should contact their Renesas technical support representative.
8. 125
°C for K version.
9. The data hold time includes time that the power supply is off or the clock is not supplied.
Table 20.5 Flash Memory (Data Flash Block A, Block B) Electrical Characteristics
(4)
Symbol Parameter Conditions
Standard
Unit
Min. Typ. Max.
−
Program/erase endurance
(2)
10,000
(3)
−−times
− Byte program time
(Program/erase endurance
≤ 1,000 times)
− 50 400 µs
− Byte program time
(Program/erase endurance
> 1,000 times)
− 65 −µs
− Block erase time
(Program/erase endurance
≤ 1,000 times)
− 0.2 9 s
− Block erase time
(Program/erase endurance
> 1,000 times)
− 0.3 − s
t
d(SR-SUS) Time delay from suspend request until
erase suspend
−−97 + CPU clock
× 6 cycle
µs
− Interval from erase start/restart until
following suspend request
650 −−µs
− Interval from program start/restart until
following suspend request
0 −−ns
− Time from suspend until program/erase
restart
−−3 + CPU clock
× 4 cycle
µs
− Program, erase voltage 2.7 − 5.5 V
− Read voltage 2.7 − 5.5 V
− Program, erase temperature -40 −
85
(8)
°C
−
Data hold time
(9)
Ambient temperature = 55°C20 −−year
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