Datasheet

Memory Characteristics
MC68HC908QY/QT Family Data Sheet, Rev. 6
Freescale Semiconductor 163
16.16 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
<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 — — 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
(2)
2. 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
(3)
3. 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
(4)
4. Typical endurance was evaluated for this product family. For additional information on how Freescale defines Typical
Endurance, please refer to Engineering Bulletin EB619.
— 10 k 100 k — Cycles
FLASH data retention time
(5)
5. 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 defines Typical Data Retention, please
refer to Engineering Bulletin EB618.
— 15 100 — Years