R8C/3GD Group

5. Electrical Characteristics

REJ03B0289-0100 Rev.1.00

Feb 26, 2010

Page 25 of 41

Notes:

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 = 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 count 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 an error occurs during block erase, attempt to execute the clear status register command, then execute 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.

Figure 5.2

Time delay until Suspend

Table 5.5

Flash Memory (Program ROM) Electrical Characteristics

Symbol

Parameter

Conditions

Standard

Unit

Min.

Typ.

Max.

Program/erase endurance (2)

1,000 (3)

times

Byte program time

80

500

s

Block erase time

0.3

s

Time delay from suspend request until

suspend

5+CPU clock

× 3 cycles

ms

Interval from erase start/restart until

following suspend request

0

s

Time from suspend until erase restart

30+CPU clock

× 1 cycle

s

READY)

Time from when command is forcibly

stopped until reading is enabled

30+CPU clock

× 1 cycle

s

Program, erase voltage

2.7

5.5

V

Read voltage

1.8

5.5

V

Program, erase temperature

0

60

C

Data hold time (7)

Ambient temperature = 55 C20

year

FST6 bit

Suspend request

(FMR21 bit)

Fixed time

Clock-dependent

time

Access restart

FST6, FST7: Bit in FST register

FMR21: Bit in FMR2 register

FST7 bit