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Electrical Specifications
Memory Characteristics
MC68HC908GR8 — Rev 4.0
Technical Data
MOTOROLA
Electrical Specifications
For More Information On This Product,
Go to: www.freescale.com
385
23.17 Memory Characteristics
Characteristic
Symbol
V
RDR
—
f
Read(1)
t
Erase(2)
t
MErase(3)
t
nvs
t
nvh
t
nvhl
t
pgs
t
PROG
t
rcv(4)
t
HV(5)
Min
Typ
Max
Unit
RAM data retention voltage
1.3
—
—
V
FLASH program bus clock frequency
1
—
—
MHz
FLASH read bus clock frequency
1. f
Read
is defined as the frequency range for which the FLASH memory can be read.
2. If the page erase time is longer than t
Erase
(Min), there is no erase-disturb, but it reduces the endurance of the FLASH
memory.
3. If the mass erase time is longer than t
MErase
(Min), there is no erase-disturb, but it reduces the endurance of the FLASH
memory.
4. t
rcv
is defined as the time it needs before the FLASH can be read after turning off the high voltage charge pump, by clearing
HVEN to logic 0.
5.
t
HV
is defined as the cumulative high voltage programming time to the same row before next erase.
t
HV
must satisfy this condition: t
nvs
+ t
nvh
+ t
pgs
+ (t
PROG
×
64)
≤
t
HV
max.
6. The minimum row endurance value specifies each row of the FLASH memory is guaranteed to work for at
least this many erase / program cycles.
7. FLASH endurance is a function of the temperature at which erasure occurs. Typical endurance degrades when the tem-
perature while erasing is less than 25
°
C.
8. The minimum row endurance value specifies each row of the FLASH memory is guaranteed to work for at
least this many erase / program cycles.
9. The FLASH is guaranteed to retain data over the entire operating temperature range for at least the minimum
time specified.
10. Motorola performs reliability testing for data retention. These tests are based on samples tested at elevated temperatures.
Due to the higher activation energy of the elevated test temperature, calculated life tests correspond to more than 100
years of operation/storage at 55
°
C
32k
—
8.4M
Hz
FLASH page erase time
1
—
—
ms
FLASH mass erase time
4
—
—
ms
FLASH PGM/ERASE to HVEN set up time
10
—
—
μ
s
μ
s
μ
s
μ
s
μ
s
FLASH high-voltage hold time
5
—
—
FLASH high-voltage hold time (mass erase)
100
—
—
FLASH program hold time
5
—
—
FLASH program time
30
—
40
FLASH return to read time
1
—
—
μ
s
FLASH cumulative program HV period
—
—
4
ms
FLASH row erase endurance
(6)
—
10k
100k
(7)
—
Cycles
FLASH row program endurance
(8)
FLASH data retention time
(9)
—
10k
100k
(7)
100
(10)
—
Cycles
—
10
—
Years
Notes:
F
Freescale Semiconductor, Inc.
n
.