R8C/20 Group, R8C/21 Group 20. Electrical Characteristics
Rev.2.00 Aug 27, 2008 Page 410 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 = 100 or 1,000), 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. Endurance to guarantee all electrical characteristics after program and erase (1 to Min. value can be guaranteed).
4. 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. 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.
5. 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.
6. Customers desiring program/erase failure rate information should contact their Renesas technical support representative.
7. The data hold time includes time that the power supply is off or the clock is not supplied.
Table 20.4 Flash Memory (Program ROM) Electrical Characteristics
Symbol Parameter Conditions
Standard
Unit
Min. Typ. Max.
−
Program/erase endurance
(2)
R8C/20 Group
100
(3)
−−times
R8C/21 Group
1,000
(3)
−−times
− Byte program time − 50 400 µs
− Block erase time − 0.4 9 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 0 − 60 °C
−
Data hold time
(7)
Ambient temperature = 55°C20 −−year
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