Datasheet

Electrical Specifications
MC68HC908GZ16 • MC68HC908GZ8 Data Sheet, Rev. 4
302 Freescale Semiconductor
21.15 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.
0—8 MHz
FLASH page erase time
Limited endurance (<1 K cycles)
Maximum endurance (>1 K cycles)
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.
0.9
3.6
1
4
1.1
5.5
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 setup 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 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
x 32) ≤ t
HV
maximum.
—— 4ms
FLASH endurance
(6)
6. Typical endurance was evaluated for this product family. For additional information on how Freescale Semiconductor
defines Typical Endurance, please refer to Engineering Bulletin EB619.
— 10 k 100 k — Cycles
FLASH data retention time
(7)
7. Typical data retention values are based on intrinsic capability of the technology measured at high temperature and de-rated
to 25°C using the Arrhenius equation. For additional information on how Freescale Semiconductor defines Typical Data
Retention, please refer to Engineering Bulletin EB618.
— 15 100 — Years