
Electrical Specifications
MC68HC908QL4  MC68HC908QL3  MC68HC908QL2 Data Sheet, Rev. 4
218
Freescale Semiconductor
17.15  Memory Characteristics
Characteristic
Symbol
Min
Typ
Max
Unit
RAM data retention voltage 
(1)
1. Values are based on characterization results, not tested in production.
2. f
Read
 is defined as the frequency range for which the FLASH memory can be read.
3. 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.
4. 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.
5. Typical endurance was evaluated for this product family. For additional information on how Freescale Semiconductor 
defines 
Typical Endurance
, please refer to Engineering Bulletin EB619.
6. 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.
V
RDR
1.3
—
—
V
FLASH program bus clock frequency 
—
1
—
—
MHz
FLASH PGM/ERASE supply voltage (V
DD
)
V
PGM/ERASE
2.7
—
5.5
V
FLASH read bus clock frequency 
f
Read(2)
0
—
8 M
Hz
FLASH page erase time 
<1 K cycles 
>1 K cycles
t
Erase
0.9
3.6
1
4
1.1
5.5
ms
FLASH mass erase time 
t
MErase
4
—
—
ms
FLASH PGM/ERASE to HVEN setup time 
t
NVS
10
—
—
μ
s
FLASH high-voltage hold time 
t
NVH
5
—
—
μ
s
FLASH high-voltage hold time (mass erase) 
t
NVHL
100
—
—
μ
s
FLASH program hold time 
t
PGS
5
—
—
μ
s
FLASH program time 
t
PROG
30
—
40
μ
s
FLASH return to read time 
t
RCV(3)
1
—
—
μ
s
FLASH cumulative program hv period 
t
HV(4)
—
—
4
ms
FLASH endurance
(5)
—
10 k
100 k
—
Cycles
FLASH data retention time
(6)
—
15
100
—
Years