Datasheet

Electrical Specifications
Memory Characteristics
MC68HC908GR8 — Rev 4.0 Technical Data
MOTOROLA Electrical Specifications 385
23.17 Memory Characteristics
Characteristic Symbol Min Typ Max Unit
RAM data retention voltage
V
RDR
1.3 ——V
FLASH program bus clock frequency — 1 ——MHz
FLASH read bus clock frequency
f
Read
(1)
1. f
Read
is defined as the frequency range for which the FLASH memory can be read.
32k — 8.4M Hz
FLASH page erase time
t
Erase
(2)
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.
1 ——ms
FLASH mass erase time
t
MErase
(3)
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 ——ms
FLASH PGM/ERASE to HVEN set up time
t
nvs
10 ——µs
FLASH high-voltage hold time
t
nvh
5 ——µs
FLASH high-voltage hold time (mass erase)
t
nvhl
100 ——µs
FLASH program hold time
t
pgs
5 ——µs
FLASH program time
t
PROG
30 — 40 µs
FLASH return to read time
t
rcv
(4)
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.
1 ——µs
FLASH cumulative program HV period
t
HV
(5)
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.
—— 4ms
FLASH row erase endurance
(6)
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.
— 10k
100k
(7)
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.
— Cycles
FLASH row program endurance
(8)
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.
— 10k
100k
(7)
— Cycles
FLASH data retention time
(9)
9. The FLASH is guaranteed to retain data over the entire operating temperature range for at least the minimum
time specified.
— 10
100
(10)
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
— Years
Notes:
Frees
cale Semiconductor,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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